JP2002325260A - Camera having display apparatus for confirmation provided with adaptative compensation of observer to reference light source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera provided with a display apparatus for confirmation for compensating adaptation of an observer to a reference light source, and its method. SOLUTION: The camera and method can be used for capturing an image of a scene which is irradiated with ambient light. The camera has a body and an electrical image sensor 84 disposed within the body. The electronic image sensor 84 captures an image irradiated with ambient light as a multicolored electronic image. A color detector 172 is disposed within the body. The color detector 172 measures ambient light to provide a color value. A lookup table 270 disposed in the body assigns color values to one predetermined light source and one or more light sources other than the predetermined light source. Light sources other than the predetermined ones respectively have a color shade relative to the predetermined light sources. A user interface disposed outside the body displays the electronic image and instructions of the light sources which assigned color values.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to photography and photography equipment, and more particularly to a camera having a confirmation display for compensating an observer's adaptation to a reference light source and a method thereof.

[0002]

BACKGROUND OF THE INVENTION Some hybrid film capture-electronic capture cameras include:
When capturing a film image, an electronic image is captured, the electronic image is displayed on a display device as a confirmation image, and what is captured in the film image is notified. It would be desirable for the verification image to provide sufficient information to the user to be able to determine whether to take corrective action, such as performing the same subject with different exposures under different conditions, instead of the previous exposure.

[0003] Many color balance problems can be easily corrected by a second exposure under different conditions, such as irradiating a flash or performing outdoors, so photographers using cameras that provide confirmation images have been I am particularly interested in the color balance of images. The color balance of a photographic latent image depends on the spectral distribution, that is, the color temperature of the light source of the scene. Terms such as "color temperature" are used herein to include both actual and correlated color temperatures. The definition of “correlated color temperature” is defined by Strobel (L.) and Zakia (Zaki).
a, R) The Focal Encyclopedia
da of Photography, 3rd e
d. , Focal Press, Boston, 199
On page 3,175, "The value assigned to a light source that does not approximate the correlated color temperature blackbody source and thus has no color temperature. The correlated color temperature is determined by illuminating a given color swatch with the light source in question and determining the color temperature of the black body source that will appear most similar to a standard observer. The color balance of the photographic latent image further depends on the type of film used. Certain types of films are configured to respond neutrally to certain light sources. A neutral response will match the spectral distribution of a given light source. For example, a "daylight" film, when exposed directly to daylight, records equal print densities for each of the cyan, yellow, and magenta film records. The resulting photographic print is printed so as to maintain a neutral response, properly color-balanced against white objects in the scene, and appears as white objects in the printed image.

When a predetermined type of film is exposed using a light source having a color balance different from that of the light source specified for the type of film, the final image obtained is tinted.
(color cast), i.e., a non-neutral response with a shifting color balance, where white objects in the scene appear colored. For example, the color in a photo print is
This means that the correlated color temperature of the "white" light source used to illuminate the print is reconstructed as something that is noticeably different. Color can be described in terms of perceived color instead of white. On daylight film, fluorescent exposures that are printed neutrally (ie, with the same print balance used for daylight exposures) have a greenish color when viewed under daylight. The image has a taste, and the tungsten exposure has a reddish orange color.

The color balance of the final photographic image produced by printing also depends on the scene balance algorithm used to control the photographic printing machine and other printing devices used. Many commercial printing systems attempt to determine the color balance of a photographic image before printing, which can compensate for the tint created by fluorescent (and tungsten) illumination. The partial compensation is generally partial because it does not degrade the high-color image unacceptably and does not select color compensation by mistakenly having different light sources. The visible tint is also perceived in the final image after partial compensation.
Stated another way, after partial compensation, the white objects in the scene seen in the final printed image are perceived as not being colored white.
This tint has an artistic effect, but in many cases the remaining tint is not desirable for the user.

Some digital still cameras and video cameras do not have this tint problem because the final image is generated by white balancing from a set of stored image data. Such images have a neutral color balance when output to an appropriately configured output device. Methods for calibrating particular devices and media are well known. Many white balance procedures are known. For example, one method of white balance is disclosed in U.S. Pat.
No. 9,357, “Auto white adjusti
ng device ". As a result of this processing, the red (R) and blue (B) code values of the digital image captured using the various light sources are changed by appropriate white balance correction parameters. These parameters determine that the R, B codes with corrected white balance are approximately equal to the green (G) codes of the white and neutral gray objects in the scene.

[0007] The human visual system adapts to light sources having different color temperatures under typical lighting conditions, as well as the white balance just discussed. ("Visual adaptation" and "adaptatio
n) "is used herein to refer to chromatic adaptation.
adaptation). Brightness adaptation (bright
ness adaptation) is included only when the effect of brightness affects chromatic adaptation. As a result, daylight, fluorescent, tungsten and some other light sources are all separately perceived as white illumination. As noted above, photographic film does not function as well as the human visual system, and photographs taken under some lighting conditions after printing are perceived as having a tint. The observer perceives the photograph as if it had passed through a color filter.

[0008] Photographers using a hybrid film capture-electronic capture camera typically adapt to ambient lighting. Therefore, when the confirmation image captured under the illumination of the fluorescent light is presented to the user without changing the color balance, the confirmation image conforms to the visual adaptation of the photographer. The white shirt looks white to the photographer whether observed directly or with the confirmation image. The problem with this method is that what the photographer observes in the confirmation image does not look the same as what the photographer observes in the final print image after printing. Since the film image cannot be white-balanced like printing, it is not useful to white balance the confirmation image. The photographer has also adapted to the surrounding lighting.

No. 08 / 970,327, filed by Miller, M. et al., Entitled "Automatic Luminance an"
dContrast Adjustment for
Display Device, by the same assignee as the present application, discloses a camera that measures ambient light levels and adjusts the brightness and contrast of an image display device on the camera.

It is therefore an object of the present invention to provide an improved camera and method for detecting the light source of a general scene and modifying the verification image to overcome observer adaptation and to show the individual colors of the captured image. Is desired.

[0011]

SUMMARY OF THE INVENTION The invention is defined in the claims. The invention, in its broader form,
A camera and method that can be used to capture an image of a scene illuminated by ambient light is provided. The camera has a main body and an electronic imaging device arranged in the main body. The electronic imaging device captures an image of ambient light as a multicolor electronic image. The color detector is located in its body. The color detector measures ambient light and provides a color value. A look-up table located in the body assigns color values to one of the predetermined light sources and one or more of the other light sources. Each of the light sources other than the predetermined light source has a tint with respect to the predetermined light source. A user interface arranged outside the main body displays the electronic image and the instruction of the light source to which the color value is assigned.

[0012] An ambient illumination is assigned to one of a set of light sources for a given scene, and the confirmation image is modified to overcome the observer's adaptation to the light source for each scene and to show each color of the captured image. It is a desirable advantage of at least some embodiments of the present invention to provide such a camera and method.

A camera according to the present invention is a camera which can be used by capturing an image of a scene illuminated with ambient light, and which is disposed in the main body and captures an image of ambient light as a multicolor electronic image. An electronic image sensor, a color detector disposed in the main body, which measures ambient light to provide a color value, and a predetermined light source, disposed in the main body, each of which has a color associated with the predetermined light source. A lookup table having color values assigned to one or more non-predetermined light sources; and a user interface disposed outside the body for displaying an electronic image and instructions of the light source to which the color values are assigned.

Further, the camera of the present invention is a camera which can be used by capturing an image of a scene illuminated by ambient light,
A main body, and an electronic imaging element disposed in the main body and capturing an image of ambient light as a multicolor electronic image, and disposed in the main body;
A color detector that measures the color value of the electronic image and has a color value assigned to one of the plurality of reference light sources to provide a reference light source disposed within the body and each having a different correlated color temperature A reference table, a control system that provides a check image by color-balancing an electronic image with a correlated color temperature of an assigned reference light source, and a display device that is arranged outside the main body and displays the check image And

The imaging method according to the present invention is an imaging method that can be used with ambient light, and captures an image of ambient light as an electronic image in a camera, measures the color value of the ambient light, and uses one predetermined light source. And one or more non-predetermined light sources are assigned a light source by adapting the color value of the ambient light. If the assigned light source is a light source other than the predetermined light source during the transfer, the electronic image is given a color correlated with the predetermined light source and the allocated light source, and a color balance is obtained.

Further, the imaging method of the present invention is an imaging method usable in ambient light, wherein an image of ambient light is captured as an electronic image in a camera, and a color value of the electronic image is measured.
Assigning a reference light source with a color value adapted to one of the plurality of reference light sources, each of the reference light sources having a different correlated color temperature, duplicating the electronic image to provide first and second reproductions; For the correlated color temperature correlated to the assigned reference light source, the color balance of the first copy of the electronic image is balanced with the color balance of the second copy of the electronic image, different from the first copy of the electronic image. And display the first and second copies of the electronic image on a display device attached to the camera.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a system 10, when a photographer activates a shutter opening unit 12 of a camera 14, a photographic subject is photographed using a confirmation imaging unit 16 and a storage imaging unit 18. The confirmation imaging unit 16 captures an electronic image of the subject image (light image of the scene).
This electronic image can be digitally processed to provide a confirmation image and displayed on a display device 20 mounted on the camera 14. The storage imaging unit 18 captures a second image to be used after printing. At the same time that the confirmation image is sent, the camera 14 informs the photographer whether the storage image provided by the printing is expected to have an acceptable color balance or an unacceptable tint. Send a signal. This signal is based on a measurement of the color value of the ambient light.

As used in this specification, "color value (color valu
The term "e)" refers to a set of properties that define a particular color stimulus in one or more multicolor systems. The stimulus has a particular continuous or discontinuous range in the one or more systems. This range is particularly called "color value range" or the like, and is abbreviated as "color value" without change within the range of the term. Each of the colorimetric systems has a known set of multiple reference color stimuli, and the reference detector or observer has a known responsiveness. Thus, a particular color stimulus has a corresponding set of reference color stimulus values defined for each color system. It is highly preferred that each of the colorimetric systems is a trichromatic system in order to reduce the required calculations, and that the reference color stimulus value being defined is a tristimulus value. In one or more color systems, the color values define a particular color stimulus and can be based on, but not limited to, human visual criteria, such as a CIE standard observer. The correlated color temperature is a color value. The color values can describe the color matching of human vision, including calibration for color systems that are not based on human visual standards. Such a calibration can also be achieved separately from the color values. For the particular use of the term "color value", one or more color systems suitable for it are defined herein. For example, the average color value of a display device is the average of the red, green, and blue (RGB) intensities, and is similar to the chromaticity, that is, the average of the chromaticity coordinates relative to a particular human reference. For convenience, color values are generally discussed in this specification for embodiments in which color matching is not an issue and visual values are the same as chromaticity. No specific terminology for chromaticity is used. For example, since a "colorimeter" measures chromaticity, the term "color detector" is used in place of the term "colorimeter" to broadly define a color measurement or evaluation device. The storage medium is color balanced for a particular color value corresponding to a given light source. Color values can also be expressed as a correlated color temperature of a given light source.

The storage imaging unit 18 holds a storage imaging medium 22 that is color-balanced with respect to a specific light source referred to as a “predetermined light source” in this specification. One example of such a medium 22 is a photographic film that is color balanced for daylight. If the ambient light for capturing the archival image matches the predetermined light source, the color balance shown in the verification image matches that found in the final archival image, such as a photographic print. The adaptation to a given light source need not be exact in some cases. For example, a daylight type film generally has a color balance with respect to strobe light. If the ambient light for the archival image is a light source having a correlated color temperature different from the predetermined light source, referred to herein as a "non-predetermined light source," it is reflected by the photographic material and captured in the archival image. The light has a color balance that deviates from a predetermined light source. Certain light sources and non-predetermined light sources are collectively referred to herein as "reference light sources." This deviation is also referred to as “color cast” in this specification. A reference light source is defined as if the human visual system could adapt to see that reference light source as white,
In this specification, it is called "adaptable".

An adaptive reference light source is within a limited color gamut and light source output defined by the human cone response. A photographer who has adapted to the adaptable reference light source regards the light source as white and does not perceive the tint. For example, if the storage imaging medium 22 is a color film that is color-balanced to daylight as a predetermined light source, a fluorescent lamp or a tungsten lamp is a non-predetermined light source that can be adapted to the medium. This is in contrast to light sources called "unadaptable light sources" such as dark room lights that do not have photochemical properties. Only the response is activated and is always perceived as white. Such light sources include daylight in a photograph having a correlated color temperature of 5500 ° K, a tungsten lamp (100W bulb) having a correlated color temperature of 2900 ° K, and a fluorescent lamp (WW) having a correlated color temperature of 3000 ° K.
F), a fluorescent lamp (CW) having a correlated color temperature of 4500 ° K
F). For convenience, the present invention generally discusses storage preservation media having daylight as the predetermined light source, and thus makes fluorescent and tungsten lamps other than predetermined light sources. This description is not limiting, and similar considerations apply to other embodiments.

Referring now to FIGS. 1, 3 and 4, the archival imaging unit 18 will now be described with reference to a photographic film capture unit 18a that generally uses photographic film 22a as a capture medium. The confirmation imaging unit 16 is an electronic imaging unit. The predetermined light source of the photographic film 22a causes a chemical reaction of the image forming layer to function.

2 and 5, according to FIGS.
8 can also capture the archival image electronically and store it in digital form. In this latter case, the "capture medium" is a digital storage medium 2 such as an electronic or magnetic memory.
2. Archival images are transferred in digital form for printing using these fully electronic capture cameras. This transfer may be on a physical medium or transmitted as an electronic signal. The two electronic imaging units may be inside the camera 14 (not shown), and the electronic imaging units may be used as both the confirmation imaging unit 16 and the storage imaging unit 18. In this case, one of the storage image and the confirmation image is obtained from the other. The storage imaging unit has a storage medium 22 provided with a predetermined light source, whatever the technology. The archival image is visualized from a latent image or stored electronic image in a printing device, which processes the image as if it were exposed by a predetermined light source. If the image has been exposed under a light source other than the predetermined light source, the resulting final archival image shows a tint.

Referring again to FIGS. 1 and 2, the archival image and the electronic image follow different routines for different times.
A final storage image and a final confirmation image are provided in the form of a display image that can be viewed. Along with the archival and verification images, camera 14 detects whether the illumination of the scene has a tint (21) and sends a signal about the tint prediction predicted in the archival image (23).

The routine 30 followed by the electronic image digitizes the electronic image after capturing (24) (26) and provides a digital image. This electronic image is calibrated (28) to accommodate differences in input / output characteristics of the components of the electronic image chain (30) and to match the characteristics of the burn-in output (32).
Next, the obtained confirmation image is displayed on the display device (20) (36). Detailed functions can be changed. For example, as discussed below, electronic images are typically stored one or more times between capture (24) and display (36) (not shown in FIG. 1).

Turning now to the film image routine 38 shown in FIG. 1, the film 22a is removed from the camera 14 following the capture 40 and additional exposure (film film).
Shown as a cartridge). Film 22a is received at a printing unit (indicated by dashed line 44), developed (46), scanned by a digital printing unit, and digitized (48) to provide a digitized image. Magnetic codes indicating the number of images to be printed,
The non-image information on or along with the film 22b is also read and used (not shown). The digitized image is digitally processed (52). Like the digital image, the digitized image undergoes a calibration conversion (5
0), corresponding to the type of input / output medium used and other input / output parameters. The resulting calibrated digital image may be printed or otherwise output in hard copy or otherwise and finished. The printing unit 44 may be optical rather than digital, in which case the developed film image is digitized or printed without calibration of the digitized image. For convenience, the discussion herein is largely limited to digital printing units. Within the limitations of the device, similar considerations apply to the optical printing unit.

The routine for archival digital images shown in FIG. 2 is similar to that for archival film images, but uses a digital memory 22b instead of film 22a (shown as a removable memory card). Do not develop. In the embodiment shown in FIG. 2, the camera 14 has a single electronic imaging unit 16 to duplicate the electronic image (2
5). One of the two resulting images is displayed (36) and the other is saved (27) and transferred for printing.

The digital image adapted to the burn channel in the camera 14 can have various characteristics. Some features of the archival image can be adapted without knowledge of the features of the burn-in channel at the time of imaging. Other features, such as partial correction of tint, require knowledge of printing parameters, such as the subject defect suppression boundary. Still other features require both knowledge of printing parameters and the transfer of additional exposures related to information from camera 14. Within these limitations, a digital image adapted to the burn channel can be provided as needed. The verification image has been modified to reduce the tint of the displayed verification image and, in the perception of the photographer, to match the tint of the final archival image after printing within the limits of accuracy discussed here It is desired to make it.

The camera 14 is shown in FIGS.
For convenience, the camera 14 will be discussed generally with reference to the embodiment shown in FIGS. Similar considerations generally apply to the camera 14 shown in the other figures, and to the camera 14.

Referring to FIGS. 3, 6, and 7, in this embodiment, camera 14 includes a film latent image capture unit 18a,
It has a main body 54 that holds the electronic imaging unit 16. The body 54 structurally supports and protects other components. The body 54 of the camera 14 can be modified to take into account forms adapted to specific use requirements. The body 54 includes front and rear covers 56,5, joined together by a chassis 60.
It is desired to have eight. Many of the components of the camera 14 can be mounted on the chassis 60. Film door 62 and flip-up flash unit 64 are rotatably connected to covers 56, 58 and chassis 60.

The storage imaging unit 18 attached to the main body 54 is a film capturing unit 18a. The film capture unit 18a has a film holder 66 and holds the film unit 42 during use. The configuration of the film holder 66 depends on the type of the film unit 42 used. The camera 14 shown in the figure is capable of reloading film, and has an APS (Advanced Photo Sy).
stem) film cartridge. The camera 14 includes an IX-DX code reader (not shown) for determining the type of film, and each film to be generated.
The data indicating the number of prints of the frame is stored in the film 22a.
It has a magnetic writer (not shown) for writing on it. This is not limiting. For example, other types of one or two chamber film cartridges and roll film, suitable cameras, etc. may be used.

The film holding section 66 includes a pair of films
Chambers 68, 70 and film chambers 68, 7
Exposure frame 72 between zero (also called "middle")
Having. Film unit 42 has a sealed can 74 located in one of its chambers. The film strip 22a is wound on a spool held by the sealed can 74. In use, the filmstrip 22a extends across the exposure frame 72 and is wrapped around a film roll 76 in the other chamber. The exposure frame 72 has an opening 78 through which a light image exposes the frame 80 of the film 22a during each capture.

The film strip 22a is moved across the exposure frame 72 by the film transport 82. As shown in FIG. 7, the film transport section 82 has an electric motor 82a disposed in a supply spool 82b, but can be driven by another type of electric drive mechanism and manually. The exposed latent image is also present during film advance or rewind.

The electronic imaging unit 16 has an electronic array imaging device 84 mounted within the body 54 and is configured to capture a scene similar to that captured in a latent image on film. Although the type of image sensor 84 used can vary, it is highly desirable that the image sensor 84 be one of several available solid state image sensors. One very common type of commonly used solid state imaging device is the charge coupled device (CCD). Some types of CC available
Two of the D's are desirable for this application because an electronic shutter can be easily implemented. The first of these frame transfer type CCDs can generate electric charge by photoactivation and moves to a non-photosensitive area where all the electric charge by the image is shielded. Next, this area is clocked out and an electronic image is sampled. The second type of interline transfer type CCD also cuts off by moving the charge, but also moves the charge to the area above or below each image line so that the same number of storage areas of image lines can exist. . Next, the storage line is retrieved in a suitable manner. Each of these CCD imagers has both advantages and disadvantages, but all can be used in this application.
A typical CCD has a clock driver, an analog signal processor (ASP) 136, and several components that function as A / D converters. An electronic imaging device manufactured by CMOS technology can also be used. It is desirable to use this type of imaging device because it is easily manufactured in readily available semiconductor processes and is suitable for use with a single power supply. Further, in that step, peripheral circuits can be integrated on the same semiconductor substrate. For example, a CMOS sensor has a single I
Clock driver integrated in C, analog signal processor 1
36 and A / D converter components. A third type of sensor that can be used is a charge injection device (CID). This sensor, unlike the others mentioned above, does not transfer charge from the element being read. Reading is realized by moving charges within a pixel. This allows for non-destructive readout of any pixel in the array. If the element is closed externally, the array can be read repeatedly without destroying the image. The shutter is realized by an external shutter, and when there is no external shutter, it is realized by injecting charges into the substrate and recombining them.

The electronic imaging unit 16 captures three color images. Single image sensor 8 with three color filters
Although it is highly preferred to use 4, a plurality of monochromatic image sensors and filters can also be used. Suitable three-color filters are well known to those skilled in the art, and in some cases provide a self-contained component incorporated into the imager 84.

Referring now primarily to FIG. 3, the camera 14 includes an optical system 86 of one or more lenses mounted within the body 54.
Having. This optical system is indicated by broken lines and multiple groups of lens elements 85. It should be noted that this is an example, and is not limited. The optical system 86 guides light to the exposure frame 72 and the electronic array image sensor 84. The optics 86 further directs light to the user, preferably via a viewfinder 88 as shown in FIG. The imaging device 84
Arranged with a gap with the exposure frame 72, the optical system 86 directs light to the exposure frame 72 along a first path (indicated by a dash-dot line 90) and further to a second path (indicated by a dash-dot line 92). Along the way, the light is guided to the electronic array image sensor 84. Both paths 90, 92 converge at the location of the subject image plane in front of the camera 14. In FIG. 3, the optical system 86 has first and second paths 90, 92 that converge on an image of the subject,
It extends to the taking lens unit 94 and the combination lens unit 96, and the combination lens unit 9
Reference numeral 6 includes both an image sensor lens unit 98 and a finder lens unit. The combination lens unit 96 has a translucent mirror 102 and divides the second optical path 92 into an imaging sub-path 92a to the image sensor 84 and a finder sub-path 92b.
The direction is changed at 4 and sent to the photographer via the eyepiece 106.

The optical system 86 can be changed. The finder lens unit and the image sensor lens unit can be completely separated as shown in FIG. 5, and the combination lens unit can have both a photographing lens unit and an image sensor lens unit (not shown). it can. Other alternative optics can be provided.

Referring again to the embodiment shown in FIG.
The taking lens unit 94 is an electric zoom lens,
The zoom drive 108 drives one or more movable members relative to one or more stationary members. Combination lens unit 96 also has one or more movable members that are driven by zoom drive 108 against one or more stationary members. The different zoom drive 108 is a controller 1 that sends a signal to the zoom drive 108 either mechanically (not shown) or
At 32, the zoom members are connected so as to perform the same zooming, and at the same time, move the unit of the zoom member to the same range or the same range of the focal length. The controller 132 takes the form of a suitably configured microcomputer, such as an embedded microprocessor with a RAM, and is capable of data processing and execution of general programs.

The taking lens unit 9 of the embodiment shown in FIG.
4 is also an automatic focus adjustment. Automatic focusing system 11
0 has a sensor 112 which sends a signal to a range adjuster 114 to operate a focus driver 116 to operate one or more focus adjustment members (not separately shown) of the imager lens unit 94. To move. The automatic focusing may be passive, active, or a combination of the two.

The taking lens unit 94 may be as simple as having a single focal length and manual focusing or fixed focus, but is not preferred. Either or both the finder lens unit 100 and the imager lens unit 98 can have a fixed focal length, and one or both can be zoomed between different focal lengths. Digital zoom (magnification of a digital image corresponding to optical zoom) can also be used instead of or in combination with the optical zoom of the image sensor 84. Image sensor 84 and display device 20
Is usually used in digital still cameras,
Instead of or in combination with the optical viewfinder 88, it can be used as a viewfinder prior to imaging.
This method is not currently preferred because battery consumption has increased significantly.

Although the camera 14 can be used in other forms, the archival image is intended to provide the basis for the final burn-in image expected by the user, and the verification image is provided later in the final image. It is intended to examine the consequences. Therefore, the confirmation image does not need to have the same quality as the storage image. As a result, in the camera 14 of FIG. 3, the imaging device 84 and the optical system 86 that guides light to the imaging device 84
Can be smaller, simpler and lighter. For example, the imager lens unit 94 is focusable, and the imager lens unit 98 has a fixed focus or can be focused between different ranges or a smaller number of focus positions.

The film shutter 118 blocks the optical path 90 to the exposure frame 72. Image sensor shutter 12
0 blocks the optical path 92 to the image sensor 84. The diaphragm aperture plates 122, 124 are connected to both light paths 90,
92. Shutter 118, 120
Can switch between an open state and a closed state.
The term "shutter" is used in a broad sense and is a physical material that provides the ability to pass light along an optical path to a film strip or imager for imaging, and to provide a function that prevents it at another time. Refers to logical members and logical members.
Thus, "shutter" includes, but is not limited to, all types of mechanical and electromechanical shutters. The “shutter” does not include a film transport unit, a mechanism for simply moving a film or an image sensor into and out of an optical path, and the like. The “shutter” includes computer software and hardware functions of the electronic array imaging device, and can start and end an imaging operation under the control of the camera control unit 132.

In the currently preferred embodiment, the film
The shutter 118 is mechanical or electromechanical, and the image sensor shutter 120 is mechanical or electronic. The image sensor shutter 120 is indicated by a broken line, and indicates both the mechanical position of the image sensor shutter 120 and the function of the electronic shutter. In the case of using a CCD, the electronic shutter of the image sensor 84 is realized by moving accumulated charges by shielding light and providing a non-photosensitive region.
This means that the whole frame is used for the frame transfer type CCD,
In the CCD of the interline transfer element, the line is a horizontal line. Suitable devices and procedures are well known to those skilled in the art. When using CID, the charge on each pixel is injected into the substrate at the start of exposure. At the end of the exposure, the charge of each pixel is read. The problem that occurs here is that the exposure time of the pixel to be read first is shorter than that of the pixel to be read last. The amount of this difference is the time required to read the entire array. This problem may or may not be significant, depending on the total exposure time and the maximum time required to read the entire array. The CMOS image sensor is shut off by a method generally called a roll shutter. This involves blocking each line separately with a common shutter time, but since the exposure time for each line starts sequentially, C
MOS imaging devices are not preferred. This means that the moving object is deformed even if the exposure time is short. In the case of horizontal movement, a vertical shape is drawn obliquely due to a temporary difference in exposure for each line. CMOS
Another method of shutting down the imaging device is disclosed in US Pat.
No. 6,297. In this method, called single frame capture mode, all pixels can accumulate charge during the exposure time. At the end of the exposure time, all pixels are simultaneously transferred to the floating diffusion of the device. At this point, the data can be read continuously for each line.

The image sensor 84 receives the light image (image of the subject) and converts the light image into an analog electric signal, that is, an electronic image, also referred to herein as a first confirmation image. (For convenience, this electronic image is generally discussed here as a single image.) The electronic image sensor 84 is operated by the image sensor driver 126. This electronic image is finally sent to the image display device 20 operated by the image display drive unit 128. There is a control system 130 between the image sensor 84 and the image display device 20.

The control system 130 controls other components of the camera 10 and performs processing related to electronic images. FIG.
The control system 130 shown in FIG.
Converter 134, image processing unit 136, and memory 138
Having. Suitable components for control systems are known to those skilled in the art. Modifications of the control system 130 include:
Useful as described elsewhere in this specification. "Memory" refers to one or more appropriately sized logical units of physical memory, such as those located in semiconductor or magnetic memory. For example, memory 138 may be internal storage such as flash EPROM memory, or removable memory such as a compact flash card, or a combination of both. The control unit 132 and the image processing unit 136 can be controlled by software stored in the same physical memory used for storing an image.
It is desired to control with firmware stored in a dedicated memory in the M firmware memory.

The first electronic image is amplified and converted into a digital electronic image by an analog-to-digital (A / D) conversion-amplifier 134, then processed by an image processing section 136 and stored in an image memory 138b. The signal line shown as the data bus 140 electrically connects the image sensor 84, the control unit 132, the processing unit 136, the image display device 20, and other electronic components.

The control unit 132 has a timing generator,
Send control signals to all electronic components that need to be timed. The calibration value for each camera 14 is
The data is stored in a calibration memory 138a such as an EEPROM and sent to the control unit 132. The control unit 132 controls the zoom drive unit 10
8, focus driver 116, aperture driver 142, film
The driving unit including the shutter driving unit 144 and the imaging element shutter driving unit 146 and the memory are operated. Control unit 13
2 is a flash circuit 148 for adjusting the flash function.
Connect to Note that the circuits shown and described can be modified in various ways well known to those skilled in the art. Also, the various functions described herein in terms of real lines can be implemented as firmware or software functions, or a combination of the two. Similarly, components shown herein as separate units can be conveniently combined or shared in some embodiments.

The electronic image for confirmation is accessed as necessary by the processing unit 136, conforms to predetermined output requirements such as constituting the display device 20 to be used, and is output to the display device 20. For example, electronic images can be processed to correct colors and color tones to achieve edge enhancement. The display device 20 is driven by the image display drive unit 128, and generates a display image to be observed by the user using the output of the processing unit 136. Control unit 13
2 facilitates the transfer of electronic images between electronic components and provides other control functions as needed.

The control system 130 further includes the display device 2
Digital processing for calibrating the confirmation image to zero is performed. Calibration involves transforming the electronic image to account for differences in properties of different components. For example, conversion is performed to correct each image, and the display device 20 of the electronic imaging unit 16
Different characteristics can be accommodated for the halftone, color gamut, and white point of the image sensor 84 and other components. Calibration is related to component features and therefore does not change from image to image. Electronic images can be modified in the same way as other digital cameras to enhance the image. For example, the image for confirmation is processed by the image processing unit 136, and interpolation and edge enhancement can be realized. The limitation here is that the confirmation image exists to confirm the storage image. Enhancements that improve or do not alter the similarity with the archival image are acceptable. Emphasis that reduces that similarity is unacceptable. If the storage image is an electronic image, both the confirmation image and the storage image can be similarly enhanced. A single electronic image can be calibrated before duplicating the verification image if necessary. Digital processing of electronic images for storage includes modifications related to file transfer such as JPEG compression and file format settings.

Further calibrating the calibrated digital image,
It is adapted to the output characteristics of a given burn-in channel and provides an adapted digital image. It is assumed that the baking-related adjustments know in advance the baking procedure to be followed for a particular unit of acquisition medium. This prior knowledge can be made available by limiting the choice of printing for a particular capture media unit, or by standardizing all available printing, or by the user, for example, , Or by setting a switch, it is necessary to select the printing means. This instruction then guides the use of a particular burning option, and the effect of the particular option can be shown directly or indirectly in the confirmation image. Application of the instructions on the capture media unit is achieved by a number of means known to those skilled in the art, such as magnetic or optical codes. Adjustment of the difference can be applied anywhere in the electronic imaging chain within the camera. Where reconciliation of differences applies in certain embodiments,
Many are a matter of convenience and constraints imposed by other features of the camera. For example, the adjustment of the printing difference is realized by a reference table which is input by a user to select a printing means. The control unit changes the color value according to a predetermined adjustment.

The control unit 132 may be implemented as a single component or as multiple components with transparent functions at various locations. Similar considerations apply to processor 136 and other components. Similarly, components shown herein as separate units can be conveniently combined or shared in some embodiments.

Different types of image display devices 20 can be used. For example, the display device 20 is a liquid crystal display device (L
CD), a cathode ray tube display, or an organic electroluminescent display (also referred to as “OELD” or organic light emitting display “OLED”). It is also desirable that the image display device 20 be activated on demand by actuation of a switch (not separately shown), or to be turned off by first pressing the timer or shutter opening 12. This timer can be realized as a function of the control unit 132. The display device 20 is preferably mounted on the back or top of the main body 54 so that the photographer can easily observe it immediately after taking a picture. One or more information display devices 150
Can be placed on body 54 to provide camera 14 with information to the photographer, such as remaining exposure, battery status, print format (C, H, or P), flash status, and the like. The information display device 150 is operated by the information display drive unit 152.
Instead of the information display device 150, the image can be provided on the image display device 20 by superimposing or replacing the image (not shown).

The image display device 20, as shown in FIG.
It is attached to the back of the main body 54. The information display device 150 includes:
Attached to the main body 54 adjacent to the image display device 20, the two display devices constitute a single user interface 154 so that the photographer can observe at a glance. The image display device 20 and the information display device 150 can be alternatively or additionally mounted so that they can be observed through the viewfinder 88 as a virtual display device (not shown). The image display device 20 can be used instead of or in addition to the optical viewfinder 88.

Since the photographer can check only what is shown on the display device 20, it is desired that the image pickup device 84 captures the image and the image display device 20 substantially displays the same geometric range as the subject as a latent image. To this end, the display device 20 displays 85-100% of the latent image, more preferably 95-100% of the latent image.
It is desired to display%.

Referring now in detail to FIG.
User interface 154 includes a “zoom in” and “zoom out” button 158.
56, which controls the zoom of the lens unit and the shutter opening unit 12. The shutter opening unit 12 is provided with the shutter 1
18 and 120 are operated. When the user opens the shutter opening unit 12 for photographing, the shutter opening unit 12 operates from the set state to the intermediate state, and then enters the open state. The shutter opener 12 is generally activated by pressing, and for convenience, the shutter opener 12 will generally be described herein with reference to a shutter button, first pressing the "first stroke" (indicated by the solid arrow 160 in FIG. 3). , The first switch 162 is activated, the shutter opening portion 12 is changed from the set state to the intermediate state, and further pressed to the “second stroke” (indicated by a broken arrow 164 in FIG. 3) to switch the second switch 166 is activated to change the shutter opening unit 12 from the intermediate state to the open state. Like other known two-stroke shutter open parts, the first stroke is
Activate automatic setting of exposure parameters such as auto focus adjustment, automatic exposure adjustment, and flash unit preparation, and the second stroke activates imaging.

Next, referring to FIG.
When the user presses 2 in the first stroke, the combination lens unit 96 and the taking lens unit 94 are moved based on the distance data of the subject sent to the control unit 132 by the automatic range adjustment unit 114 (the range adjustment unit in FIG. 3). Each,
Automatic focus adjustment to the distance of the detected subject. Control unit 132
Receives data from one or both of the zoom drive unit 108 and a zoom sensor (not shown) indicating the focal length of the zoom lens unit. The camera 14 further comprises a film unit detector 1
Using 68, the film speed of the film cartridge 42 loaded in the camera 14 is detected, and this information is transmitted to the control unit 132. Camera 14 obtains the scene brightness (Bv) from components that function as illuminometers, discussed below. The brightness of the scene and other exposure parameters are
2 to determine the focal length, shutter speed, aperture diameter, and possibly gain settings for amplifying the analog signal provided by the image sensor 84. Appropriate signals for these values are
Drive unit 116, film and image sensor aperture drive unit 1 via a motor drive interface (not shown)
42, the film / shutter drive unit 144, and the image sensor shutter drive unit 146. The gain setting is A /
D conversion-sent to amplifier 134.

In the camera 14 shown in FIG. 3, the captured film image provides the archival image. In another embodiment shown in FIG. 4, the archival image is an electronic image and the capture medium is a removable memory 22b. The type of removable memory used, such as optical, magnetic or electronic, and the information storage method are not important. For example, the removable memory may be a floppy disk, CD, DVD, cassette tape, or flash memory card or memory stick. In this embodiment, the electronic image is captured and then duplicated. The first electronic image is used as a verification image, and the second electronic image is stored on the capture medium to provide a storage image. System 10 is another method similar to system 10 described above, except that printing does not include chemical development and digitization, as shown in FIG. In a complete electronic camera 14, the verification image may be a low resolution subset sampled from the archival image, and a second low resolution electronic array imager (not shown)
Can also be used. A low-resolution subset of archival images is described in commonly-assigned U.S. Pat. No. 5,164,831 to Kuchta et al.
IC STILL CAMERA PROVIDING
MULTI-FORMAT STORAGEOF F
ULL AND REDUCED RESOLUTIO
N IMAGES ", the disclosure of which is incorporated herein by reference.

The camera 14 shown in FIG. 5 can be used as a capture unit for storage, based on the choice of the photographer, the storage space available on one or another capture medium 22, or some other criteria. Either the unit 18a or the electronic imaging unit 16 can be used. For example, mode switch 170 can provide another film capture mode and an electronic capture mode. Camera 1
4 also operates in the same manner as in the previous embodiment.

The camera 14 uses the image sensor 84 and / or a separate detector 172 (shown in dashed lines in the figure) to determine the ambient illumination level and the ambient light color corresponding to the color temperature of the scene light source. Evaluate the value. 2 to 5 show the image pickup device 8
4 with an electronic imaging unit 16 including an ambient light detector 172 (shown in broken lines as an attached function)
Is shown. The detector 172 has an ambient light detector drive 173 that operates a single sensor 174 or multiple sensors (not shown). The term "sensor" includes an array of sensors. The sensor is referred to herein as "single" or "multiple" based on whether the ambient light detection separately measures light received from different portions of the surrounding area. A "single sensor" can have separate photodetectors for different colors. An ambient light detector or sensor can receive light from optical system 86,
Irradiation from outside the optical system 86 is also possible.

The color balance is determined using the image sensor 84, and the brightness of the scene is determined using the ambient light detector 172. (It is also possible to use the image sensor 84 for brightness and the ambient light detector 172 for color balance, but it is not preferable.) Also, use either the image sensor 84 or the ambient light detector 172. Thus, both values can be detected. The camera 14 can also be configured to selectively alter the use of the image sensor 84 and detector 172 for different user requirements, such as abnormal lighting conditions.

Each scheme has advantages and disadvantages. Using the imager 84 reduces the complexity of the camera 14 in terms of component count, but increases the complexity of the digital processing required for the captured image. Imager 84 is shielded from direct illumination by overhead light sources that provide ambient illumination. Detector 172 with one or more sensors that receive light from optical system 86 has the same advantages.
The separate detector 172 has the advantage of simplifying digital processing and can split some functions. For example, the detector 172 includes a first ambient light detector that determines the brightness of the scene to calculate the exposure setting before exposure, and a second sensor (not shown) that determines the color value at the time of exposure. Can have. The use of the imaging element can reduce the number of components of the camera 14. Information processing procedures for scene brightness and color balance can be combined for more efficient operation. This combination has the disadvantage that the load on digital processing increases when only partial information is needed, such as when exposure settings are required before the image is exposed.

One example of a suitable ambient light detector used to provide one or both of the illumination and color values of a scene and separate from the electronic imaging unit 16 is disclosed in US Pat. No. 4,887,121. And is shown in FIG. The detector 172 faces in the same direction as the lens opening 175 of the taking lens unit 94 of the camera 14. The detector 172 is connected to the photographing lens
Unit 94 receives light directed toward an image of the scene captured. Ambient light enters window 176 and is directed to liquid crystal mask 180 by first light pipe 178. The second light pipe 182 receives the light sent through the liquid crystal mask 180 and divides the light into a series of different color filters 184.
(Preferably red, green, and blue). Filter 18
A photodetector 186 located on the other side of each of the four connects to the control system 130. The liquid crystal mask 180 is controlled by the control system 130, and transmits light uniformly to all the photodetectors 186 for color measurement. The liquid crystal mask 180 provides a grid (not shown) that can be partially shielded in different ways, so that exposure measurements in different patterns can be realized.

The electronic imaging unit 16 is connected to a separate detector 17
It can be used instead of 2 to get the brightness and color balance value of the scene. In this method, captured electronic image data is sampled, and scene parameters are determined from the data. When an automatic exposure function such as an automatic setting of a shutter speed or a diaphragm setting is used during imaging, the electronic imaging unit 16 needs to obtain a peripheral illumination level before imaging. This can be done by providing the electronic imaging unit 16 with an evaluation mode and a capture mode. In the evaluation mode, the electronic imaging unit 16 captures a sequence of electronic images. These images are captured as long as the shutter opening 12 is activated via the first stroke and is held in that position. The electronic images can be stored in memory, but are typically discarded one after the other when capturing alternative electronic images to reduce memory usage.
The verification image is usually obtained from one of this series of electronic images, which is performed simultaneously with the archival image within the limits of the camera shutter. That is, the confirmation image is provided before the photographing and at the end of the continuation of the electronic image captured simultaneously. It is also possible to use one or more parts of a series of evaluation images instead of or in conjunction with the last image to provide photometric data during the exposure process and to provide the data needed to detect color. it can. As used herein, the term "confirmation image" includes images provided by either method, but for convenience, the confirmation image is generally described herein as being obtained from the last electronic image. The term "evaluation image" is applied before the capture of the archival image,
It is used here to identify a portion of a series of electronic images that do not contribute or only partially contribute to the confirmation image.

The image for evaluation can be sent to the image display device 20 used by the photographer before photographing in the composition of the photograph. The evaluation image may or may not include the color signal. Providing a tint signal has the advantage that more information is given to the photographer in advance, and how to proceed thereafter can be determined better. On the other hand, this increases energy consumption and may provide the photographer with information that is rarely used immediately, even though the photographer is dedicated to composing the photograph. It is now desirable that the camera 14 not display the evaluation image because the use of the display device 20 for this purpose increases battery consumption and the optical viewfinder 88 can provide similar functionality with minimal battery consumption. .

The electronic image pickup unit 1
6 is calibrated during assembly to achieve illumination level measurements using known illumination levels and imager gain. Control unit 1
32 can process data provided to the evaluation image using the same type of illuminance measurement algorithm used for the multi-spot illuminometer. This procedure is repeated for each of the subsequent evaluation images. Each pixel or group of pixels replaces each sensor used in a multi-spot luminometer. For example, the control unit 132 can determine the maximum illuminance of the image by comparing each pixel until a maximum value is found. Similarly, the controller 132 can determine the overall intensity, which is the arithmetic average of all pixels in the image. Many measurement algorithms provide an average or integrated value of only a portion of the array of imaging elements 84. Another approach evaluates multiple regions and weights the regions separately to provide an overall value. For example, in a center-weighted system, the center pixel is weighted more than the surrounding pixels. The camera 14 can be manually switched between different schemes such as center-weighted or spot measurement. Camera 14 also
The measurement method can be automatically selected based on the content evaluation of the scene. For example, an image with a large horizontal bright area at the top can be interpreted as sky and a specific weight can be given to the rest of the image.

Under appropriate lighting conditions, the image sensor 84
Illuminance measurement and color balance can be determined from a single evaluation image. More extreme lighting conditions are addressed using multiple portions of a series of evaluation electronic images while changing the exposure parameters until an acceptable electronic image is captured. How to change the parameters is not important. The following method is convenient. When measuring an unknown scene, the image sensor 84 is set to an intermediate gain, and a predetermined image area is sampled. If the image exceeds a certain upper threshold (TH), such as over 220, assume that the gain is too high and make a second measurement at half the gain of the first measurement (one stop less). (The values of TH and TL given here are examples and are based on a maximum of 8 bits or 255 per pixel.) If the second measurement is one half of the previous measurement, then the measurement is accurate and representative. It is considered to be. If the second measurement is still higher than TH, the process is repeated until a measurement having a value half that of the previous measurement is obtained. If the first measurement is less than the lower threshold (TL), such as 45, the gain is doubled and a second measurement is performed. If the measurement obtained is twice that of the first measurement, the measurement is considered to be accurate and representative.
If this is not the case, the gain is doubled again and the measurement is repeated as in the case of the upper threshold. Exposure parameters, such as aperture setting and shutter speed, can be similarly changed separately or in combination with changing the gain. In limited cases, such as complete darkness, the electronic imaging unit 16 cannot capture an acceptable image. In these cases, the evaluator sends an error signal to the user interface 154 to inform the user that, under existing conditions, the camera 14 cannot provide adequate illumination measurement and color balance. Suitable algorithms and functions for these schemes are well known to those skilled in the art.

After receiving the value of the brightness of the scene, the control unit 132 compares the brightness of the scene with the flash activation point. If the light level is below the flash activation point, the control 1
Numeral 32 denotes a flash unit 64 for providing full illuminance.

The camera 14 can determine the ambient illuminance level and the color value of the ambient light at each capture. Also, to preserve the digital processing, the camera 14 can measure ambient light or check recent exposures before performing any processing. Referring to FIG. 28, after the first stroke (188) activates the first switch 162, the camera 14 finds that the time delay after the previous exposure is less than a predetermined value (19).
0), the camera 14 retrieves the previously stored color values (19)
2). If the time lapse is greater than a predetermined value, the camera measures the ambient light (196) and records the resulting color value (1).
98). The searched or evaluated color value is sent to the control unit (20).
0). Images for storage and confirmation are captured (206), and when the timer starts (202), the next exposure is performed after a lapse of time (204). The same procedure can be followed for illumination levels, or both color values and illumination levels.
This scheme assumes that ambient light does not change appreciably over short elapsed times. The appropriate elapsed time depends on the use of the camera, with longer times increasing the risk of errors and shorter times increasing the processing load on the camera during a series of exposures. For normal use, an elapsed time of less than one minute is desired. The elapsed timer is camera 1
When 4 is turned off, it is always reset.

In another second method, also shown in FIG. 28, the color signal is invalidated when a flash is used. The flash unit 64 provides a near daylight light source and can be treated as providing daylight in many embodiments disclosed herein for tint signals. This method is shown in FIG.
As shown in FIG. 8, it can be used with the second method of elapsed time just discussed. The color signal is the brightness of the scene
If the (lumimance) is very high, the very high light level can also disable the color signal in some cases, assuming that the camera is exposed outdoors in daylight lighting (Not shown). These second approaches are implemented by software or firmware (not separately shown) in the control system and can be combined with other embodiments of any of the methods previously discussed. In the second method, for example, the color value and the light level are measured every time, and the elapsed time is guaranteed, or if the flash is used, it can be modified so that only the digital processing step is omitted.

The camera 14 provides a signal that the archival image is expected to have a tint. The signal may be exemplary or non- exemplary. In the case of the exemplary signal, the camera 14 indicates at least roughly the effect of the tint directly in the confirmation image. In the case of a non-exemplary signal, the camera 14 presents only an indication 360 that the archival image shows a tint. The effect of the color on the storage image corresponding to the confirmation image is left to the imagination of the photographer.

Exemplary Signals Referring now to FIGS. 3-20 in greater detail, the camera 14 that provides the exemplary signals allows the photographer to directly observe the expected tint or an approximation of that tint. The electronic image is modified and the captured electronic image provided by the camera 14 is immediately used by the photographer, and the captured image is printed, after printing, an archival image having an acceptable color, acceptable configuration and other features. Can be determined. Human visual adaptation involves displaying a confirmation image that has been modified for the ambient light from which the picture was taken, and increasing the color so that the photographer can perceive it sufficiently despite the adaptation of the photographer to the ambient light. Will be overcome. This correction is also referred to herein as "color adaptation de-compensation", which increases the tint for the initial verification image (and for the expected burn-in archival image), so The opposite result of balance. As a result, the displayed confirmation image does not actually have the color balance seen in the final storage image, but for a visually adapted photographer, the confirmation image is the final storage image It appears to have a color balance, or approximate color balance. Therefore, the photographer can determine whether or not the tint exists in the final storage image, and if so, can determine whether or not to take an improvement measure such as repeating photographing using a camera flash.

The image display device 20 provides a color image of sufficient quality in these embodiments, and allows the photographer to adjust the color to the reflected light from the predetermined light source and the color from the other light source that can be expected to adapt. Compensated colors for reflected light can be distinguished. Suitable image displays provide the emitted light either directly or using a backlight. This light has a changeable white point and implements the range of chromatic adaptation de-compensation provided by camera 14. Unacceptable image display devices are those that have a more limited white point range or use ambient light reflections for illumination.

Referring to FIG. 8, exemplary signals are actual illumination (actual) and what the photographer observes (perceived).
Are shown in two columns. For simplicity, the discussion herein is limited to the photographer, ie, the person using the camera 14. Similar considerations apply to other people viewing the confirmation image. The columns in FIG. 8 are connected by arrows 210 indicating that the photographer's visual system has adapted to the indicated ambient light. The theme 212 is observed with ambient light (213).
An image is taken (214). Ambient light is adaptive non-predetermined illumination emitted by the fluorescent lamp 216 and reflected by the subject. Confirmation image 21 sent on image display device 20 of camera 14
8 is then observed with the same ambient light (220), and also after a time delay or other action (222) in daylight (indicated by the sun mark 224) (221). The predetermined light source for the stored capture image (not separately shown in FIG. 8) is daylight.

When the photograph is taken, the subject 212 is illuminated with fluorescent light. In the actual row, the reflected light from the captured subject 212 is represented by “color of fluorescent light” 228 indicating the color balance of the light source of the fluorescent light. The photographer's visual system, represented by eye 230, is exposed to adaptation and considers the adaptable non-predetermined illumination reflected from subject 212 to be white. In the perceived column, this is represented by “white illumination” 232.

After the photograph of the subject 212 is taken, a confirmation image 218 immediately after the photograph is displayed on the display device 20 on the camera 14. (The embodiment of the camera 14 shown in this figure provides a confirmation image that doubles the tint detected by ambient light. In this discussion, this embodiment was selected for simplicity. Embodiments operate in a similar manner.) Camera 14 remains in the same ambient light that captured the archival image. The photographer remains adapted to the surrounding non-predetermined illumination, and considers the light reflected on the back 226 of the camera 14 to be white illumination. In the actual column, the reflected light from the rear surface 226 of the camera 14 used is a “color of fluorescent light” 22 indicating the color balance of the light source of the fluorescent light.
It is represented by the term 8. In the perceived column,
The reflected light from the back 226 of the camera 14 used is represented by the term "white illumination" 232, which indicates the color balance seen by the photographer.

Referring again to the actual columns, the display device 20
Shows the confirmation image 218 immediately after correction to compensate for the adaptation of the photographer to ambient lighting. This is represented by the term "doubled fluorescent lamp color" 234. Referring to the perceived row, the photographer observes "white illumination" on the back of the camera, and the display device 20 sees what is the color after printing. (In the column of perceptions, this is indicated by "fluorescent tint" 228.) The tint that becomes invisible due to the visual adaptation of the photographer is restored by this compensation. What the photographer observes is not accurate, but close enough for the photographer to accurately determine whether the captured film image is acceptable.

In addition to the confirmation image immediately after, the camera 14 can also provide a "confirmation image after the passage of time" 236, where the color is displayed without compensation. Following the time delay or due to user arbitration (indicated by the arrow (222) in FIG. 8), the camera 14 replaces the confirmation image immediately after actuation of the switch 238 with the confirmation image after the passage of time. Replace with The confirmation image 236 after the lapse of time does not compensate for a light source other than the predetermined light source provided during shooting. To change from the image for confirmation immediately after to the image for confirmation after a lapse of time,
In many cases, it is based on the assumption that the user changes the position and inputs different ambient light conditions after taking an image. Since the new lighting conditions are unknown, the best response is
It is assumed that the predetermined light source (daylight in FIG. 8) is the main light source and that the user adapts to that light source.

The switch 238 is indicated by an arm 238 a having the position of the confirmation image immediately after indicated by “A” 240 and the position of the confirmation image after the lapse of time indicated by “B” 242. This switch can have a mechanical timer. The arm 238a has two positions 240, 2
It is manually movable between 42 and automatically moves from position "A" 240 to position "B" 242 following exposure of the image under the action of mechanical timer 244. ("A", "B"
Are not shown, and a movable switch contact that moves with the arm between the two fixed contacts is not shown. ) Arm 238a can be manually or automatically reset to position "A" 240 when the next image is captured. Digital circuits that provide the same function can be easily replaced with the switches shown.

In FIG. 8, following a time delay or switch activation, the camera 14 is illuminated by daylight 224. The photographer adapts to the surrounding daylight lighting. The photographer considers the daylight illumination reflected on the back of the camera 14 (the actual row of "daylight illumination" 246) to be white illumination (the perceived row of "white illumination" 232). Display device 20
Displays a confirmation image after a lapse of time, that is, an uncompensated electronic image having a tint ("the tint of a fluorescent lamp" 228 in the actual column) with respect to daylight illumination. The photographer perceives the tint (“the tint of fluorescent light” 228 in the perceived row). The photographer can again determine from the confirmation image whether the captured storage image is acceptable after burning.

In the embodiment just described, the confirmation imaging unit 16 prepares and displays the immediately following confirmation image 218, and the confirmation image 248 after the lapse of time.
And a second mode for preparing and displaying the.

In the embodiment shown in FIG. 9, the electronic imaging unit further has a third mode for preparing and displaying the digitally transferred image 250. The digital transfer image 250 is not used for confirmation. Digital transfer image 250
Starts with the first electronic image capture (24). The electronic image is digitized (26) and duplicated (252).
One of the duplicates is the confirmation image 218 immediately after, as described above.
(Not shown in FIG. 9). Other copies are calibrated for use as digital files (25
4). This replica is not calibrated to match the output characteristics of the print. Digital transfer image 250 obtained
Is stored in memory as a digital file (25
6) It can be retrieved from memory and used like any other digital image file.

Since the digitally transferred image is color-balanced not for use as a confirmation image but for output as a digital file, the digitally transferred image is modified so that it is independent of the corresponding storage file. The appearance of digitally transferred images can be optimized. For example, the control system 130 of the camera 14 can include a white balance controller (not separately shown) operably connected to the image processor 136 and the controller 132. The white balance controller corrects the color balance of the electronic image to a predetermined reference such as daylight.

The digitally transferred image is displayed on the display device 20 and directly from the memory via an output port (not shown).
Alternatively, it can be digitally transferred to another digital device or a storage medium via a network, and used or printed as a digital image. Digitally transferred images can also be physically transferred on removable memory. Image memory includes temporary storage such as one or more fixed storage, volatile or non-volatile memory, DRAM buffer memory, and the like.

The camera 14 can have a mode switch 170 so that the user can selectively display a digital transfer image instead of a confirmation image. (Mode switch 170
Can implement one of a plurality of functions as necessary. ) The detailed function of the mode switch is not important and can be changed. For example, a convenient mode switch (not shown) for multiple functions is a digital keypad.

When the user selects the display of the digital transfer image 250, the image 250 is retrieved from the storage device, calibrated (259) and displayed on the image display device 20 (3).
6). As part of this process, the tint signal is nullified (260). In the case of the exemplary signal, disabling is accomplished by omitting the modification of the electronic image, displaying the tint in the ambient light, and possibly removing the tint by white balancing.

Exemplary Signal: Compensation for a Matched Reference Light Source Referring now to FIGS. 10-13, in some embodiments of the camera 14 described above, the tint in the ambient illumination is the measured ambient light color. Correcting the confirmation image to one color balance of a group of predetermined reference light sources selected based on the value is indicated directly in the confirmation image. In the methods and systems of FIGS. 10 and 11, an image of ambient light is captured using a storage medium 22 with a predetermined light source (40). The ambient light image is further captured as an electronic image in camera 14 (24). The color value of the ambient light is measured (262) and adapted to one of a predetermined group of reference light sources (264) and a light source is assigned. The reference light source includes one or more of a predetermined light source and a non-predetermined light source. Each reference light source has a corresponding compensation. Following the adaptation (264), compensation corresponding to the assigned light source is provided to the control system 130 (266),
The compensation is applied (268).

Compensation can also be applied to previously captured electronic images, in which case the images are stored in memory and modified by an image processor. Compensation can also be applied to the next captured electronic image,
In this case, a correction is made before storing the electronic image in the memory. (See, for example, FIGS. 15 and 16) Compensation may be a modification of the acquisition process. In this case, no image processor is used to correct the image. (See discussion at the bottom of FIGS. 13 and 14) For convenience, the present invention is generally discussed herein with respect to modifying stored electronic images, but similar considerations apply when modifying images at the time of capture. Is clear.

The electronic image is calibrated (28) and adapted to the characteristics of the burn-in output 34, corresponding to the differences in the input / output characteristics of the components of the electronic imaging chain (32). The obtained confirmation image is further displayed on the display device 20 (36).

Confirmation image 21 displayed on display device 20
8 balances the color perceived by the reference light source with respect to the predetermined light source. That is, the electronic image is modified so that the photographer who has adapted to the predetermined light source displays what he or she perceives when looking at the scene captured and illuminated by the specific reference light source. The color image displayed on the display device 20 allows the photographer to distinguish whether or not there is a color on the confirmation image even when the surrounding illumination from the light source other than the predetermined light source that can be adjusted continues.

If the reference light source to be used is a light source other than the predetermined light source, the light source is actually corrected so as to have a tint with respect to the predetermined light source, and further, the light source other than the predetermined light source is corrected. The resulting tint can be perceived by the photographer despite being visually adapted to a particular non-predetermined light source. If the reference light source used is a predetermined light source, there is no color, and the confirmation image is not changed by the color balance.

The compensation of the confirmation image can be performed with high accuracy for various light sources and combinations of light sources, but it is not necessary in normal use. The confirmation image only needs to have sufficient accuracy in hue and intensity so that the photographer can determine whether or not to take improvement measures. The tint in the confirmation image may be different from the tint in the final storage image, but the tint shown in the confirmation image is almost the same as the tint shown in the burned storage image. Is desired. Further, it is also desired that different light sources other than the predetermined ones show different colors in the confirmation image. In addition, it is highly desirable to assign each of the tints shown in the confirmation image to a particular reference light source to better match the tints generated by the light sources in the archival image than the tints generated by different light sources. . For example, if daylight is a predetermined light source, it is desirable that the color shown in the confirmation image be orange for a tungsten light source and green for a fluorescent light source, and both are the same. Or it is not desired that the tungsten lamp be green and the fluorescent lamp be orange.

The color compensation range provided in the confirmation image is a minimum enough for the photographer to perceive the color in contrast to the color perception adapted by the photographer. It is desirable for the photographer to know the expected result of printing. Although full accuracy is not possible, a good approximation to different lighting conditions is that the photographer should be It is realized by color balance of perceived color. With a limited number of predetermined light sources, the required color change value can be easily determined experimentally using known color matching techniques. Such values can also be obtained by inverting the white balance vector, as described later in this specification.

The number of different light sources and light source combinations to be compensated for depends on the expected use of the camera 14.
If the camera 14 is limited to daylight film and normal consumer photography, compensation for a small number of light sources is sufficient. In many applications, the light source is limited to daylight, tungsten lamps, and fluorescent lamps. Fluorescent lamps do not have a constant color temperature, but vary depending on the phosphor used in the tube. A plurality of different mixtures are commonly used, each having a characteristic color temperature, but with the photographic daylight (correlated color temperature of 5).
There is no color temperature close to 500 ° K). Tungsten lamps change as well.

In some embodiments, the camera 14
There is a single value for each of daylight, tungsten lamp, and fluorescent lamp lighting. For example, fluorescent lamp lighting uses a correlated color temperature of 4500 ° K for lighting of all fluorescent lamps, and the photographer's ability to perceive the color of the fluorescent lamp in the immediately following confirmation image does not deteriorate. Absent.

In a specific example, camera 14 is a daylight
There are two non-daylight sources that can be used with the film to adapt. The reference table 270 of the camera 14 is shown in FIG.
In the form of an RGB color space diagram. In the figure, the relative intensities of red (R), green (G) and blue (B) are plotted linearly, with each color varying between 100% of the indicated vertex and 0 on the opposite side. Three points on FIG. 270 are a predetermined light source 272 and two non-predetermined light sources 274, 27.
6 is shown. The predetermined light source 272 has a correlated color temperature of 5
Daylight at 500 ° K. One non-predetermined light source 274
Is defined as fluorescent light illumination with a correlated color temperature of 4500 ° K. The other non-predetermined light source 276 is defined as tungsten illumination with a correlated color temperature of 2900 ° K. The lookup table 270 is divided into a fluorescent lamp area 278, a tungsten area 280, and a daylight area 282 as shown in the figure. All light sources that are detected to be predominantly fluorescent, that is to say having a relative RGB value defining a point within the area 278 of the fluorescent light, have a correlated color temperature of 4500 ° K.
In the same manner as the fluorescent lamp. All light sources that are predominantly tungsten lamps, that is, having a relative RGB value within the tungsten region 280, will be treated similarly to tungsten lamps with a correlated color temperature of 2900 ° K. The remaining light sources whose measured color values are not compatible with fluorescent or tungsten lamps and have relative RGB values in daylight region 282 have a correlated color temperature of 55
Treat in the same way as daylight at 00 ° K. Therefore, this embodiment does not accurately match the confirmation image with the tint of the final printed image, but is relatively simple and easy to implement, and is practical for normal use. The generated confirmation image is close to the tint of the final image after printing. For photographers,
Sufficient information is obtained that can reasonably determine whether a second exposure is made to improve the previous color balance problem.

Fluorescent lamps and tungsten lamps are available in a plurality of different correlated color temperatures and are standardized to provide uniform results for many types. The camera 14 and method can be modified from that described in detail herein, if necessary, to closely match many different adaptable non-predetermined light sources. In many applications, the predetermined light source is daylight with a correlated color temperature of 6500 ° K. Another predetermined light source, such as a tungsten lamp with a correlated color temperature of 2900 ° K, may be provided to accommodate other types of films.

The color evaluation is performed by a color detector 172 (shown in broken lines in FIG. 13), which has a drive 173 which can be provided as a separate circuit or as part of the control unit 132. The color detector 172 evaluates the color value of the surrounding illumination. The color detector 172 is used in conjunction with the look-up table 270 to classify or distinguish light sources in the scene to match a color temperature range assigned to one of a predefined set of reference light sources. The color detector 172 and the lookup table 270 together implement a light source discriminator 286. The light source identifier 286 performs a “difference adjustment” to the control system 130 of the camera 14 and then modifies the electronic image at several stages of the electronic image chain within the camera 14. If the assigned reference light source is a light source other than the predetermined light source, the color balance of the electronic image is changed by adjusting the difference, and the color of both the predetermined light source and the allocated light source is notified. If daylight is the predetermined light source, changing the color balance will lower the color temperature for the original electronic image. If the assigned reference light source is the predetermined light source of the storage medium, the adjustment of the difference does not change the color balance of the electronic image. In this and other embodiments, the camera 14 may be set to not perform any processing operations, and may not change the image or only slightly change the image. In this case, if the predetermined light source is the reference light source, the color balance is omitted. Similarly, color values adapted to a given light source can be color balanced for the given light source, and color matching is omitted. The latter is desirable because digital processing is reduced and the confirmation image remains the same color balance as the scene image and the photographer's adaptation.

There are several different ways for the color detector 172 to determine the color temperature of the light source of a scene from a digital image of the scene. Different methods will achieve the same result in some cases, but may differ for light sources used in other cases. In the "grey world" method, if all colors are averaged together in any scene, the result is gray, that is, no color. The shift from gray indicates the color. This type of color detector can determine the color by arithmetically averaging the values of all the red, green, and blue pixels together and comparing the result to a range of values in look-up table 270. The average color value of a scene is sometimes referred to herein as the single "color temperature" of that scene. Whether or not the selected unit for a color value has dimensions is not important as long as the same system of units is used throughout the process and appropriate conversions are performed as needed. For example, a color value may be expressed as a correlated color temperature of ° K, a designated light source characterized by such a color temperature, and a gain adjustment for each of the three color channels.

The theory of the gray world is very well maintained in some scenes, but does not work well in others. For example, images of white sand, bright blue sky and the sea do not average gray. Similarly, indoor scenes with blue walls do not average gray. These types of problematic scenes can be handled by adding color determination steps that are guided to perceive the condition of the given problem. Due to these drawbacks, a color detector 172 using the gray world scheme is acceptable but not preferred.

In another "brightest object" scheme, the brightest object, that is, the one with the highest luminance,
Assume that it must be a color neutral object reflecting the light source of the scene. The pixel of the brightest object is arithmetically averaged and compared with the value in the lookup table 270. The brightest object can be located by examining the pixel values in the scene. A variety of different procedures can be used to determine which pixels to average. For example, there is a case where 5% of the total number of pixels is the percentage of the brightest pixels, or all the pixels having brightness twice or more the average brightness are out of the brightness of the entire scene. In some cases, all pixels are above a certain percentage, or in some combination, such as pixels that are twice as bright as the average, but less than 5% of all pixels. . In certain embodiments, pixels are combined into groups (paxels) in a pixel accumulator.
One example of a typical paxel is a 36 × 24 block of pixels. The pixel accumulator averages the logarithmically quantized RGB digital values and provides an array of RGB paxel values for each paxel.

If the pixel values are very high when performing the above pixel measurements, the electronic imaging unit may be saturated.
In this case, the gain of the electronic imaging unit is reduced, and the scene is photographed again. This procedure is repeated until the value decreases in proportion to the gain reduction. This can be done in various ways. In a particular embodiment with 8-bit pixels, if the brightest pixel has a value of 240, reduce the gain by 2 and re-capture the scene. That same pixel is examined again. If the value has decreased, this indicates that the image sensor 84 is not saturated, and that the data of the pixel is valid. Red (R), green (G), and blue (B) pixel values are obtained, and if the pixel data is determined to be valid, the red and blue values and the green and blue values are determined. Calculate the ratio of values. These ratios correspond to the color values to be compared with the ranges in lookup table 270.

A suitable “brightest object” type color detector 17
2 and an example of its operation are shown in FIGS.
After the electronic image is captured (24), digitized (26), and stored in the frame storage unit 289, the peak value detector 2
90 quantifies the pixel (292) and determines the highest pixel value (294). If the value exceeds a predetermined threshold, eg, 240 in the above example, level adjuster 295 reduces the overall “gain” (eg, sensor exposure time, or electronic amplification factor) of electronic imaging unit 16 by approximately one-half. , And the image sensor 84 captures another image (24). Next, this image is converted to digital (26) and stored (2).
88). This pixel data is examined again by the peak value detector 290 (292). If the peak value detector 290 confirms that the peak value does not exceed the threshold (294), they are grouped into the brightest part (paxel) in the pixel accumulator 300 as described above (298). If the peak value exceeds the threshold, the gain is reduced again and the process is repeated until acceptable data is obtained. The paxels drawn in the pixel accumulator 300 are red in the combiner 304,
Green and blue are combined (302) to provide a combined average for red, green, and blue in the brightest areas of the image. These averages are combined (306) in a color ratio calculator 308 to calculate the ratios of red and blue and green and blue in a ratio circuit. These ratios can be found in Lookup Table 2
Providing (309) color values for comparison with the 70 reference ranges.

Other "Brightest Object" Type Color Detector 284
Also available. For example, another suitable color detector 1 of this kind
No. 72 is disclosed in U.S. Pat. No. 5,659,357.

When the color values are sent from the color detector 172 to the look-up table 270 and compared with the values in the table, the look-up table 270 indicates that the reference Adapt the color values to the values in the set.
Scene light source values in look-up table 270 can be obtained experimentally from a particular camera model by illuminating a neutral scene with a standardized light source, recording the camera response, and calculating corrections.

The term "look-up table 270" refers to both the device and software necessary to complement logical memory in one or more computing devices, and to control and implement access to logical memory. Lookup table 270
Can store a set of pre-calculated final values and can combine these schemes. For convenience, the look-up table 270 is generally described herein in the form of a storage of pre-calculated values for light sources of different scenes. Similar considerations apply to other types of lookup tables 270.

The values of the scene illuminant in look-up table 270 may take various forms, and the values may be used to adjust for differences to directly control one or more components of the electronic imaging chain, or It depends on whether it is an input to the algorithm that adjusts the difference next. In practice, which one to use is a matter of convenience and of constraints imposed by computational features in the design of the particular camera 14.

For example, the value of the light source of the scene is
2 can be obtained from the white balance circuit used. The white balance correction is pre-calculated for each different reference light source for a given light source and provided in a look-up table as a scene light source value. In this case, white
The balance circuit provides a color value for comparison with a value in a look-up table using the color detector 172 as before. The look-up table is a small white
A balance correction is assigned to adapt a larger correction to one of the plurality of non-predetermined light sources.

As described above, in certain embodiments of the present invention, the predetermined light source is daylight having a correlated color temperature of 6500 ° K, and the two non-predetermined light sources have a correlated color temperature of 3500 ° K.
A K fluorescent lamp and a tungsten lamp having a correlated color temperature of 2900 ° K. In this embodiment, the reference table 270
Correlates the color temperature range of each light source. These ranges include a plurality of different light sources, such as a fluorescent lamp and a tungsten lamp (and daylight), and the imaging unit 1 for confirmation of the camera 14.
6 can be derived by combining the respective results.

Here, the value of the light source of a scene is generally described as the correlated color temperature of the light source of a predetermined scene. These color temperatures are input to an algorithm that calculates the required difference adjustment. This description is intended to assist in understanding the general features of the invention. Although the scene light source values are provided in this form, the adjustment of the differences required for a particular camera 14 using a particular type of storage medium 22 includes:
It is generally more efficient to pre-calculate to associate the values of the scene's light sources. As a procedure in this direction, the value of the light source of the scene is calculated as the color shift of the correlated color temperature of the light source of the scene with respect to the correlated color temperature of the predetermined light source.
It may be explained here. As another procedure, the adjustment of predetermined differences, such as color channel gain, for one or more components of the electronic imaging chain from the array of imaging elements 84 to the display device 20, the value of the scene light source, is described herein. Sometimes.

Adjustment of the differences provides a change in the color balance of the verification image that partially or completely overcomes the effects of adaptation of the human visual system to the light sources of a particular scene. It can be very close to what the photographer perceives as being the same as the actual tint produced in the final archival image, but this need not be the case in normal use. This method also has a problem when the light colliding with the eyes of the photographer has a different color temperature from the light source of the scene of the image for storage. This may occur, for example, with a camera lens system 86 having a narrow field of view used for illumination from a mixed scene light source. A better approach for normal use is to provide only those that are close to the tint generated in the stored image after printing.

The currently preferred method is to use a lookup table 27
To adapt the range of the scene light source to a small number of zero reference light sources. One of the reference light sources is a predetermined light source, and the other reference light source is a light source of a type generally encountered. In typical indoor and outdoor applications, at least one reference light source in the look-up table has a correlated color temperature greater than 5000 K, assigns it a daylight illumination color value, and assigns at least one reference The light source should have a correlated color temperature of less than 5000K.

For example, in a specific embodiment, the color temperature 35
A color value corresponding to 00 to 4500 ° K is a correlated color temperature of 450.
Compatible with 0 ° K CWF fluorescent light source, color temperature 3500 °
Color values corresponding to less than K are compatible with tungsten lamps having a correlated color temperature of 2900 ° K, and color values having a color temperature greater than 4500 ° K are suitable for daylight having a correlated color temperature of 5500 ° K.

In the scheme just described, both color temperature ranges map to a continuous range of color temperatures. Instead, a discontinuous area can be provided, and the missing area can be assigned to daylight or to a message that the confirmation image cannot show approximately the same color balance (image display 20 or information It is displayed on the display device 50).

For storage media that is color-balanced to daylight, it is generally desirable that flash illumination, or at least illumination from flash unit 64 of camera 14, be assigned to daylight in look-up table 270. This can be easily performed by causing the camera 14 to send a flash-on signal to the lookup table 270 when the flash 64 is used. This flash-on signal
The color value signal from the color detector 172 is overwritten, and daylight is assigned as the light source of the scene. The reason for this is that there is a close relationship between the correlated color temperature of daylight and the strobe lighting provided by the flash unit 64. With different storage supplements, such as film with a tungsten lamp color balance, this relationship is not maintained and the daylight can be used as a light source for the scene, either by measuring the light emitted by the flash or by using the flash-on signal again. Must be assigned.

The value of the scene light source is used by the control system 130, which includes a control unit 132 and an image processing unit 136, to control one or more components of the electronic imaging chain. The value of the light source of the scene is used directly or indirectly by an algorithm in the control unit 132 and / or the processing unit 136 to adjust the difference. Adjustment of the difference does not result if the light source is assigned to daylight or another predetermined light source.

Referring again to FIGS. 14 and 15, in a particular embodiment, the value of the scene light source is sent from look-up table 270 to controller 132 and then sent to channel gain adjuster 311 for conversion to RGB channel gain. (313). This channel gain is sent to the image sensor 84 (315). The control unit checks whether the switch S2 166 is closed. If closed, images for confirmation and storage of the scene are captured (319). The electronic image is converted to a digital format (26) and stored in the frame storage unit 289 (288). The obtained digital image is sent to the display drive unit (319) and displayed on the display device as a confirmation image (3).
6). The display timer is started (321). The control unit checks whether the timer has expired (323), and turns off the display device when the timer expires (325). The control unit is
Further, it is checked whether the first switch S2 162 is closed, and if it is closed, the timer is turned off (325), and this cycle is repeated for the next exposure.

The amount of compensation provided, ie, channel gain or color shift in some other form, can be determined in various ways. The simplest is by trial and error using the standard light source of the camera 14. The reduction in printing tint can be accounted for by a final archival image generated using camera 14 and a standard light source and a second trial and error using the desired printing process.

If very high accuracy is required for compensation, color values can be predicted using a transform that models human visual adaptation, such as the Von Kries transform. The von Cries transform converts the user's XYZ tristimulus values adapted to a certain light source to the user's corresponding XYZ tristimulus values adapted to a second light source. The von Cries transform follows the conversion of tristimulus values from a first light source a to a second light source b.

According to the von Cries transform, Y = 1
At 00, X and Z are calculated from x, y chromaticity coordinates.

The von Kries transform is defined as follows.

X + y + z = 1 Therefore, z = 1−xy X = x (Y / y) = x (100 / y) Z = z (Y / y) = z (100 / y) von Kries matrix (here Then "vK") is (Equation 1)
Becomes

[0121]

(Equation 1)

The parameters ρ, γ, and β are human cone response values. The conversion is (Equation 2).

[0123]

(Equation 2)

Exemplary Signal: Inverse White Balance Correction Referring now to FIGS. 15-20, in another embodiment, the camera 14 converts color values to values in a predetermined look-up table to provide inverse chromatic adaptation compensation. Do not match. Instead, the camera 14 determines a color space vector that defines the white balance correction, determines a second color space vector in the opposite direction to the white balance correction, and then determines a neutral color space vector on the color space inverse vector. Color balance the electronic image to the points. (The changes made to this color balance are referred to herein as "inverse white balance correction.") Unless modified by adjustment (discussed below), the inverse white balance correction has a magnitude equal to the color space inverse vector. Become. The reverse white balance correction can be determined without first determining the white balance correction, but since this method can use various known white balance circuits, the current white balance correction is determined first. It is then desirable to calculate the inverse white balance correction.

The white balance correction is related to the neutral point of the storage medium 22. Therefore, applying the white balance correction to the electronic image is to balance the color of the electronic image with respect to the correlated color temperature of the predetermined light source in the storage medium 22 for storing the gray image in the color space. It has a color value of a neutral point (also referred to as a “white point”) of a predetermined light source in the figure. This gray object appears colorless or white to an observer visually adapted to a given light source.

FIGS. 15 to 18 show an example of this method. The photographs were exposed under tungsten lighting (on film that was color balanced to daylight) and the camera 14
No flash is used. Electronic imaging device 84
Captures the image of the scene as an electronic image and then A /
It is digitized by the D converter 134. This electronic image is R
It is sent to memory 138b in the form of GB (red, green, blue) code values. The white balancer evaluates the code values and determines a white balance correction to provide a D55 white point. (D55 is a standard light source of the International Commission on Illumination (CIE), which represents one type of daylight illumination, and is referred to as "Daylight in Photography".
Is commonly called. Therefore, the daylight film is D
D55 is the predetermined light source for this film, color balanced to 55 illuminations. FIG. 17 shows how to determine whether or not the white balance correction determined by the color adjuster 310 should be applied to the digital image on the RGB color space diagram. For a neutral gray object, the average code value is R >> B before white balance, and B
Is multiplied by a factor much larger than the value of R, so the average code value after white balance operation is R = G =
B. The image neutral point of the object is the color space vector 3
From 12, the white point 314 of the tungsten lamp (indicated by a circle) moves to the white point 316 of D55 (indicated by a circle). FIG. 18 shows what is obtained when inverse white balance correction is applied to a digital image. The neutral point of the image of the object is opposite to the white balance,
A new neutral point 320 along the color space inverse vector 318
(Here, also referred to as “compensation point” 320). In this case, the compensation point is the end point of the color space inverse vector 318. The color balance moves the neutral point of the image away from the D55 white point and the neutral point of the tungsten lamp, resulting in a distinct tint for an observer who has adapted under the ambient illumination of the tungsten lamp.

The camera has a color adjuster 310 for determining the color balance adjustment. In the embodiment shown in FIG. 15, the color adjuster 310 is a white balance circuit 322.
(Also referred to as “white balancer 322”) and an inverting circuit 324. The particular white balance circuit 322 used is not critical. Various white balance circuits are known to those skilled in the art and can be used in camera 14 taking into account computing power, memory requirements, power consumption, size limitations, and the like. Many white balance circuits simply adjust the balance of RGB code values so that the average value is colorless. This method is not preferable because the color balance should be based on the light source of the scene, not the overall color balance including the contents of the scene. A preferred white balance circuit evaluates the color of the light source in the scene.

One example of a suitable white balance circuit of this type is disclosed in US Pat. No. 5,659,357. Similar circuits are shown in FIGS.
Is shown in The white balance circuit 322 has a block representative value calculation circuit 326, into which an RGB digital image signal is input from an image signal input terminal 328. As shown in FIG. 19, the block representative value calculation circuit 3
At 26, the image signal is divided into a plurality of blocks 350, and a block representative value of each divided block is obtained. The blocks have a square shape and are arranged regularly according to a division method. The block representative value calculation circuit 326 obtains the value of the image signal included in each divided block as a block representative value. For example, all the pixels (R, G,
The average value of the signal from B) is used as the RGB representative value. Also, an average value of signals from predetermined pixels in a block (for example, every four pixels in every four lines), or a median value or a mode value of pixel signals of the block can be used as an RGB representative value.

The block representative value obtained by the block representative value calculation circuit 326 is calculated by the fluorescent lamp block average value calculation circuit 33.
0, the tungsten light block average value calculation circuit 332, the daylight block average value calculation circuit 333, the brightest block search circuit 338, and the brightest block average value calculation circuit 340 are each processed through a predetermined procedure.

In the fluorescent lamp block average value calculation circuit 330, a block representative value included in the fluorescent lamp white signal area is calculated by:
A block representative value is selected from among the block representative values obtained by the block representative value calculation circuit 326, and the average and the number of predetermined block representative values are respectively determined.
Obtained as a fluorescent lamp block average value and the number of fluorescent lamp blocks. The fluorescent lamp white signal region is defined as a region where image signals from a white object irradiated by the fluorescent lamp are distributed. The fluorescent lamp block average value calculation circuit 330 sums up the number of predetermined block representative values and obtains the number of blocks (the number of fluorescent lamp blocks) whose representative values are included in the fluorescent lamp white signal area.

Tungsten light block average value calculation circuit 3
A block 32 selects a block representative value belonging to a tungsten light white signal area from all block representative values, and a predetermined block representative value (tungsten light block average value).
And predetermined number of blocks (number of tungsten light blocks)
Get. The tungsten light white signal area is defined as an area in which an image signal from a white object irradiated by light from a tungsten lamp is distributed.

The daylight block average value calculation circuit 333 selects a block representative value belonging to the daylight white signal area from all the block representative values, and calculates a predetermined block representative value (daylight block average value) and A predetermined number of blocks (the number of daylight blocks) is obtained. The daylight white signal area is defined as an area in which image signals from a white object illuminated by daylight illumination are distributed.

The brightest block search circuit 338 selects the brightest block from all the blocks of the image signal. The brightest block is the block representative value R,
G and B components have the brightest brightness in a block in which each of them indicates a predetermined R, G, and B threshold or more. The brightest block search circuit 338 outputs the brightest block representative value (the brightest block representative value). In a particular embodiment, the brightest block search circuit 338 uses its R,
A block whose G and B components are larger than respective predetermined R, G and B thresholds is selected, and a block having the brightest luminance is selected from the selected blocks as the brightest block of the image signal. The luminance L is expressed by (Expression 3) or (Expression 4)
Defined by

[0134]

(Equation 3)

Or

(Equation 4)

The luminance defined by an equation other than the above equation can be used. The brightest block search circuit 338
The representative value of the brightest block (the brightest block representative value) obtained by the selection is output to the brightest block average value calculation circuit 340.

The brightest block average value calculation circuit 340
Obtains the brightest block signal area based on the brightest block representative value input from the brightest block search circuit 338. The area where the brightest block representative value of the predetermined color is distributed is defined as the brightest block signal area. A method for obtaining the brightest block signal area will be described with reference to FIG. The brightest representative value entered is plotted on the DG-DI plane 346. D
The values of the G348 axis and the DI350 axis are defined by (Equation 5) and (Equation 6).

[0138]

(Equation 5)

[0139]

(Equation 6)

The values in the DG-DI plane 346 (DI-BR,
(DG-BR) is calculated from the R, G, and B component values of the brightest block representative values in (Equation 5) and (Equation 6). The line connecting the origin and the point (DI-BR, DG-BR) is DG-DI
Set in plane 346. A rectangular region 352 including the line segment and having sides parallel to the line segment is defined as the brightest block signal region (FIG. 5). In this example, the length of the side parallel to the line connecting the origin and the point (DI-BR, DG-BR) is a predetermined multiple of the length of the line, and the length of the side orthogonal to the line is The length is predetermined. Both lengths can be determined by trial and error.

The brightest block average value calculation circuit 340
Selects a block representative value included in the brightest block signal area from the block representative values input from the block representative value calculation circuit 326, and calculates an average value of the predetermined block representative values (the brightest block average value) and a predetermined value. Is obtained (the number of the brightest blocks).

The fluorescent light block weighting circuit 334 calculates a fluorescent light block weighting coefficient based on the input data from the fluorescent light block averaging circuit 330. The fluorescent light block weighting circuit 334 multiplies the fluorescent light block average value and the fluorescent light block number by a fluorescent light weighting coefficient to obtain a weighted fluorescent light block average value and a weighted fluorescent light block number.
When inputting the average fluorescent lamp block value and the number of fluorescent lamp blocks from the fluorescent lamp block average value calculating circuit 330 to the fluorescent lamp block weighting circuit 334, the luminance of the theme is determined by the fluorescent lamp block weighting circuit 334 from the theme luminance input terminal 343.
To enter.

The fluorescent light block weighting circuit 334 calculates a fluorescent light block weight coefficient based on input data through a predetermined procedure. An example of a method of calculating the weight coefficient is shown below.
V, the average value of the fluorescent light block is (RF, GF,
F), the saturation amount of the fluorescent lamp block average value is denoted by SF.
The saturation amount S is defined by (Equation 7).

[0144]

(Equation 7)

The fluorescent light block average value (RF, GF,
The DI and DG values for BF) are obtained by (Equation 5) and (Equation 6). SF is the above obtained DI, DG
It is obtained by multiplying the value by (Equation 7).

According to this weighting factor determination method, a smaller fluorescent lamp block weighting factor WF is set when the luminance of the subject is higher, and is generated from a white object illuminated by a fluorescent lamp and green grass under sunlight. Prevents fading. The high brightness of the subject indicates a bright subject, indicating that the subject is not illuminated by a fluorescent lamp but is under sunlight. An image signal obtained from green grass under sunlight may be included in a fluorescent lamp white signal region other than that from a white object irradiated with the fluorescent lamp. If the brightness of the subject is high,
The effect of white balance adjustment on the subject illuminated by fluorescent lamps must be reduced by reducing the fluorescent lamp block weighting factor, which weights the fluorescent lamp block average to a small value close to zero. I do. The fluorescent light block weight coefficient can be determined using predetermined thresholds BV0, BV1, BV2, and BV3 according to the following rules.

(1) If BV <BV0, WF = 1.0 (2) If BV0 ≦ BV <BV1, WF = 0.75 (3) If BV1 ≦ BV <BV2, WF = 0 .5 (4) If BV2≤BV <BV3, WF = 0.25 (5) If BV3≤BV, WF = 0.0 where B
V0 <BV1 <BV2 <BV3.

In the above rule, WF is the brightness BV of the subject.
Is determined only based on The essence of this determination method is that when the luminance BV of the subject is high, the fluorescent light block weight coefficient W
That is, F is set to a small value, and if the saturation amount is sufficiently small, it is set to 1 regardless of the luminance value of the subject.
Further, the fluorescent light block weight coefficient can be set to a small value regardless of the value of BV if the saturation amount SF is very large. Instead of the above rule, a predetermined function f (RF, G
F, BF) can be used to obtain SF.

The fluorescent light block weight coefficient W obtained by this method
F allows the following: If the brightness BV of the subject is low, it means that the subject may be illuminated by a fluorescent lamp, and the influence of the illumination of the fluorescent lamp is removed by white balance adjustment. A higher brightness BV of the subject means that the subject may be green grass under daylight, and the white balance adjustment for fluorescent light is reduced.

The fluorescent light block weighting circuit 334 multiplies the fluorescent light block average value and the fluorescent light block number by the determined fluorescent light block weighting coefficient.

Tungsten light block weighting circuit 33
6 calculates a tungsten light weighting coefficient based on the tungsten light block average value inputted from the tungsten light block average value calculation circuit 332 through a predetermined procedure, and calculates the tungsten light block average value and the number of tungsten light blocks, The weighted tungsten light block coefficient is multiplied to obtain a weighted tungsten light block average value and the number of weighted tungsten light blocks.

The daylight block weighting circuit 337 calculates the daylight block weighting coefficient based on the daylight block average value input from the daylight block average value calculation circuit 333 through a predetermined procedure, and calculates the daylight block average value. Value and the number of daylight blocks,
The daylight weight coefficient is multiplied to obtain a weighted daylight / tungsten light block average value and the number of weighted daylight blocks.

The average value of the brightest block and the number of the brightest blocks are obtained by calculating the brightest block average value calculation circuit 340.
To the brightest block weighting circuit 342.

The brightest block weighting circuit 342
Calculates the brightest block weighting factor based on the brightest block average, multiplies the brightest block average and the number of brightest blocks by the brightest block weighting factor, and calculates the weighted brightest block average and Get the number of weighted brightest blocks.

The above-described circuits, ie, the block average value calculation circuits 330, 332, 333 and the block weighting circuits 3324, 336, 337 can be used for white balance adjustment, but the brightest block search circuit 338 and the brightest circuit Block average value calculation circuit 334,
And by including the brightest block weighting circuit 342, it is desirable to consider even brighter blocks in the white balance.

The average value of the daylight and tungsten light blocks is calculated by the daylight and tungsten light block weighting circuit 3.
36 and 337, respectively. The daylight and tungsten light block weighting circuits 336 and 337 determine daylight and tungsten light block weight coefficients, respectively, based on input data through a predetermined procedure. For example, the daylight or tungsten light block average is (RD, GD,
As BD), the saturation amount of the daylight or tungsten light block average can be denoted as SD. The saturation amount SD is obtained from (Equation 7) similarly to the above-described SF. According to this determination method, the daylight or tungsten light block weight coefficient WD is set to a small value when SD is large.

In addition to the above rules, other methods for determining the daylight and tungsten light block weighting factors WD can be employed. For example, instead of the above rule using SD, WD may be a predetermined function f (RD, GD, BD) with variables of daylight or tungsten light block averages (RD, GD, BD). BD). The daylight and tungsten light block weighting factors obtained according to this method ensure that the white balance is not over-adjusted when the human eye cannot fully adapt to the surrounding conditions, such as sunset.

Tungsten light block weighting circuit 33
6 multiplies the average value of the tungsten light blocks and the number of tungsten light blocks by the determined tungsten light block weighting coefficient, and the daylight block weighting circuit 337 calculates the daylight block average value and the determined number of daylight blocks by the daylight block weight. Multiply by the weighting factor.

The average value of the brightest block and the number of the brightest blocks are calculated by the average value calculation circuit 340 for the brightest block.
To the brightest block weighting circuit 342. The brightest block weighting circuit 342 obtains the brightest block weight coefficient based on input data through a predetermined procedure.

For example, the average value of the brightest block is (R
B, GB, BB), the saturation amount of the brightest block average is indicated as SB. Saturation amount SB
Is obtained from (Equation 7) similarly to SF. This method of determining the brightest weighting factor WB uses a predetermined threshold S0
B, S1 Determined from the following rules using B:

(1) If SB <S0 B, WB = 1.0 (2) S0 B ≦ SB and (B B ≧ RB or 2
* If GB-R B-BB≤0, WB = 0.0 (3) S0 B <SB≤S1 B and (BB <R
B and if 2 * GB-RB-BB> 0) then WB
= 1.0 (4) S1 B <SB and (BB <RB and 2 *
If GB-RB-BB> 0), WB = 0.75
Here, S0 B <S1 B.

According to this rule, the brightest block weighting factor is BB≥RB or 2 * GB-RB-BB
Set to 0 when ≤0. The brightest block representative that satisfies the above condition indicates that the image may be obtained from a blue sky. Under these conditions, white balance adjustment using a single brightest block weighting factor strongly reflects the condition of the brightest block and easily causes fading. The above description is an example of a method for determining the brightest block weight coefficient. The brightest block weight coefficient can be appropriately determined depending on usage conditions such as which light source is mainly used and which subject is mainly imaged.

The brightest block weighting circuit 342
Multiplies the average value of the brightest block and the number of the brightest blocks by the determined weighting factor.

White balance adjustment signal calculation circuit 34
4 calculates a white balance adjustment signal based on the weighted values obtained from the fluorescent light block weighting circuit 334, the tungsten light block weighting circuit 336, the daylight block weighting circuit 337, and the brightest block weighting circuit 342. I do. The white balance adjustment signal calculation circuit 344 combines the fluorescent light, daylight, tungsten light, and the weighted block average value in proportion to the weighted number ratio of the brightest block, and based on the combined value, determines the white balance. Obtain the adjustment signal. In this calculation, the contribution ratio (combination ratio) of the fluorescent light, daylight, tungsten light, and brightest block to the white balance adjustment signal is first calculated from (Equation 8), (Equation 9), and (Equation 10). can get.

[0165]

(Equation 8)

[0166]

(Equation 9)

[0167]

(Equation 10)

Here, MF, MD and MB are a fluorescent light block, a daylight / tungsten light block,
And the combination of the brightest blocks.
CNTF, CNT D and CNT B are the number of fluorescent light blocks, daylight / tungsten light blocks, and brightest blocks, respectively. W * CN for each of the above equations
T is a weighted number of the block. The combining ratio is the ratio of the weighted number of blocks of one light source (fluorescent, daylight / tungsten light and one of the brightest lights) to all blocks.

A mixed signal (Rmix, Gmix, Bm
ix) is based on the combination ratio of each light source,
1), (Equation 12) and (Equation 13).

[0170]

[Equation 11]

[0171]

(Equation 12)

[0172]

(Equation 13)

The white balance adjustment signals Radj, Badj
Is based on the three components of the mixed signal,
Obtained by

[0174]

[Equation 14]

Instead of using the above Radj and Badj, M
After obtaining AX = max (Rmix, Gmix, Bmix), MAX-Ranix, MAX are used as white balance adjustment signals.
-Gmix and MAX-Bmix can be used. The operator max (a, b,...) Means to select the maximum value from all values in parentheses.

In this embodiment, the image signal information of the brightest block can affect the white balance adjustment. Therefore, the white balance adjustment signal (and the inverse white balance adjustment signal) can be appropriately determined for an image obtained from a subject illuminated by a light source other than a predetermined light source.

Referring again to FIG. 16, the calculation result of the white balance adjustment signal is sent to the inverting circuit 324, where the inverse vector of the white balance adjustment signal is calculated using (Equation 15), and the inverse white balance is calculated. Control signal,
That is, it provides reverse white balance correction.

[0178]

(Equation 15)

The inverse white balance adjustment signal is sent to a color balance adjustment circuit 354 (also called a color balance adjuster 354), and the white balance of the input image signal is adjusted using the inverse white balance adjustment signal. . The color balance adjuster 354 adds a color balance adjustment signal to each of the R and B components of all pixels, adjusts the color balance, and provides a compensated image, that is, a confirmation image showing the compensated color.
The color balance adjustment circuit 354 further outputs a compensated image, that is, a confirmation image, via the compensation signal output terminal 356.

As in the other embodiments described, print tint corrections or other adjustments can be added to this color adjustment procedure in a separate procedure, or in combination with other modifications of the electronic image. Such modifications can be accommodated by assigning standard adjustments to all decisions or by using appropriate look-up tables for different adjustments. Such a look-up table can be used to input the type of film, color values, etc., to make different reductions in baking tint or make other adjustments. The input may be manual, using a film sensor, or a combination of the two. In any case, it is highly desirable to maintain the compensation point on the inverse color space vector while changing the magnitude of the inverse white balance correction. This procedure shifts the hue, may confuse the user with the perceived light source, and further affects the actual printing operation. For example, some printing procedures reduce color by 80%, while images printed from color negative films do not change the hue of the remaining colors. This can be accommodated in the camera by calculating an 80% reduction in the magnitude of the reverse white balance correction, and when color negative film is used in the camera or always making this correction.

In the illustrated embodiment, the attached automatic white
The balance adjustment circuit 346 adjusts the white balance of the input image signal using the white balance adjustment signal. R obtained by adjusting the white balance
The GB image, that is, the transfer image, is output from the image signal output terminal 348 that has achieved white balance.

Automatic White Balance Adjustment Circuit 346
Adds a white balance adjustment signal to each of the R and B components of all pixels, adjusts the white balance, and provides a transfer image for later electronic transfer. This copy can be displayed if desired and can be modified into the form of email and other digital images used for other electronic transfers. For example, an electronic image is Exif / J
It can be stored as a compressed file of a specific format such as a PEG image file. If necessary, the white balance correction parameters can be stored with the shared image and reconverted to an image without white balance.

Non-Exemplary Signals Referring now to FIGS. 22-27, 29 and 31, in certain embodiments, the camera 14 shows an indirect indication 360 that the archival image has a tint. In these embodiments, the camera 14 displays a confirmation electronic image having a color balance that is perceptually adapted to the original scene, or a color balance that is independent of the original image. The presence of the tint in the printed storage image is indicated by an instruction 360 that does not depend on the color balance of the confirmation image.

Referring to FIG. 22 and FIG.
Captures the image of the scene illuminated by the fluorescent light,
0), the fluorescent lamp is a light source other than the predetermined light source of the storage image capturing medium 22 (shown by a broken line in FIG. 23). The image of the scene is captured as an electronic image on the storage medium 22, and the electronic image is processed as described above and displayed on the display device 20 as a confirmation image. This confirmation image has a color value that is not different from the detected color or a color value that is changed by white balance. (The image for storage does not receive white balance.) The photographer who has adapted to the ambient light having a tint cannot perceive the actual tint appearing in the image for storage in the image for confirmation. The color tint due to the illumination is detected by any of the above-described methods (361), and an instruction 360 indicating that the color is present in the image for storage after printing is displayed together with the confirmation image (363).

In a preferred embodiment, the color detector averages the red, green and blue (RGB) signals from the electronic image sensor and compares their signal intensities to determine the primary colors red, green, and red in the RGB signal combination. Determine the green, blue, or white / neutral point. The user interface provides instructions to inform the user about the predetermined color unless the predetermined color is below the cutoff, otherwise the user is informed of the white / neutral color. The current preferred cutoff point is 60% of the total intensity of the combined RGB signals.
White / neutral balance is “red”, “green”, or “blue”
Can be exchanged because there is no signal. This scheme has the advantage of simplicity, signaling the color in the scene due to ambient light and the fact that there is a large amount of one color in the scene content. This scheme compares within the red, green, and blue signals and can be modified to provide different ratios of these signals to determine primary colors other than red, green, and blue.

The instruction 360 is provided by a separate instruction display device 362.
It can be displayed on the top, or can be superimposed (combined) within the confirmation image displayed on the image display device 20.
In either case, the indication 360 may be an indistinguishable color patch, at least at a wavelength substantially corresponding to the color value of the ambient illumination, or an alphanumeric message or a non-alphanumeric indication. Algorithms for displaying instructions on the display device 20 and synthesizing the instructions 360 in the image are well known to those skilled in the art. For example, a very simple algorithm replaces the pixels of the confirmation image with the pixels of the instruction 360 (see FIG. 23).

FIG. 29 is a partially enlarged view of the schematic view of the camera shown in FIG. 3, which has been modified to have an instruction display device 362 and an instruction display drive unit 364. It is connected to the control unit 132 via a line 366. FIG. 23 shows the outside of the same camera 14, a separate indication display 3 carrying the word "COLOR CAST" and radiating outwards as dashed lines.
62 is shown. These words and the dashed line are an alphanumeric instruction 360 and a color patch instruction 360, respectively. The relative positions of the image display device 20, the information display device 150, and the instruction display device 362 can be varied to suit the spatial and aesthetic needs of a particular camera design. The shape and size of the instruction display device 362 can also be changed. In the embodiment shown in FIG. 26, the instruction display device 362 is located around the image display device 20 and shows color patches indicating the tint predicted in the image for storage. The same type of components as the image display device 20 can be used for the instruction display device 362. The choice of components of the instruction display 362 is not important. For example, FIGS. 24 and 25 show a self-luminous display device such as an OLED for the image display device 20 and a lamp 369.
Shows the camera 14 having the second information and instruction display device 365 using the LCD 368 with the backlight as a backlight.

In the embodiment shown in FIG. 23, in addition to the image display device 20 and the information display device 150, an instruction display device 362
Having. The instruction display device 362 is another method as shown in FIG.
It can be combined with the information display device 150 as shown in FIGS. 4 and 25, or can be combined with the image display device 20 as shown in FIG. The tint indication 360 is displayed in all of these alternative ways as well as a color patch or indication. The camera 14 shown in FIG. 31 has an alphanumeric instruction 360, and combines the word "COLOR CAST" on the confirmation image. FIG. 26 has a color patch around the confirmation image, and the display device for the image and instructions 360 is the first and second portions of a panel 371 that is continuously pixelated. In this case, both the color patch and the confirmation image are displayed on the image display device 20. Algorithms for combining text or color patches with the confirmatory image for display on a single display device 20 are well known to those skilled in the art. Camera 14 shown in FIGS.
Form a transfer image. The switch 368 is operatively connected to the control unit 132 so that the user can check the confirmation image (indicated by “V”) and surrounding color patches,
Alternatively, only the transfer image (indicated by “T”) can be selected on the display device 20.

User Interface Ambient Light Detector Referring now to FIGS. 30-33, the camera 14
It can be modified to include a user interface ambient light detector 370 located at the user interface 154, which detects ambient light with the eyes of the photographer viewing the image on the display device, rather than the ambient light when capturing the scene. It can be so. The user interface ambient light detector 370 includes an image sensor 84 used to determine the exposure setting, or a separate light sensor 172 (here, "Scene ambient light detector 1").
72). The user interface ambient light detector 370 may modify the color image of the electronic image to modify the confirmation image, particularly to overcome the user's visual adaptation at the time the image is viewed, to provide an exemplary color image. This is particularly advantageous in the case of a camera 14 providing a taste signal.

FIGS. 31 and 32 show a camera 14 having a user interface ambient light detector 370. FIG. The detector 370 has a user interface peripheral sensor driver 372 and one or more sensors 374. Although the sensor driver 372 is shown in FIG. 32 as being separate from the ambient light sensor driver 173, these functions can be combined into a single sensor driver (not shown). . The user interface ambient light detector 370
It is necessary to separate from the image sensor 84. One or more sensors 374 of the user interface ambient light detector 370
Can be arranged in the viewfinder 88, but independent of the optical system 86, and the image display device 2
It is desirable to approach 0. In certain embodiments, the sensor 374 is mounted on the upper back of the camera body 54, as shown in FIG. 31, to help ensure the accuracy of the user interface and the measurement of ambient light in the user's eyes. Within these limitations, the user interface ambient light detector 3
The 70 may use a single member sensor or a multiple member sensor, as discussed above for the scene perimeter detector 172. The camera 14 can further use a second image sensor as the sensor 374 of the user interface ambient light detector 370. The second image pickup device is an image pickup device 8 used in the electronic image pickup unit 16.
The resolution may be much lower than 4.

FIG. 30 shows how to use the camera 14 having the user ambient light detector 370. User 2
12 is observed (213) and an image is captured under fluorescent light (214). Next, the confirmation image 218 is observed under the same fluorescent lamp as the captured image (214) (220). After changing to a tungsten lamp (indicated by the symbol of the tungsten lamp 373) (371), the user checks the image 21 for confirmation.
8 is observed again (376). Since the lighting conditions are the same, the actual and perceived columns of FIG. 30 are similar to those shown in FIG. 8 captured and immediately observed under fluorescent light illumination. FIG. 8 does not show the observation after the passage of time under tungsten illumination. In the case of the camera of FIG. 8, the result is suboptimal, since the adaptation of the user to the tungsten illumination is not compensated. On the other hand, in FIG.
4 compensates for the illumination conditions at the time of observing the confirmation image. Therefore, after changing to the peripheral illumination (375), the camera illuminates with a tungsten lamp (tungsten illumination 377), and the confirmation image shows a color compensated for the tungsten illumination ("Fluorescent lamp compensated for tungsten"). 378), the user observes the same fluorescent light tint 228 as under other ambient light conditions. FIG. 30 is exemplary. The camera 14 operates similarly to other lighting, as discussed above, within the limitations imposed by the given reference light source and other camera features. For example,
Observation of the confirmation image under daylight is similar to that shown when the confirmation image after the lapse of time in FIG. 8 is observed under daylight.

The confirmation image is provided as a copy of the image stored in the memory. This replica is color balanced to match the current ambient light and is shown to the user when the switch is activated, preferably based on the user's choice. After the display, that is, when the camera user changes modes or turns off the camera, the color balanced copy is discarded. The stored image is held separately from the confirmation image until the user transfers or deletes the image.

User Interface Ambient Light Detector 370
Provides the color values used in the same manner as described above, and modifies the electronic image to overcome the user's visual adaptation. Each time an electronic image is displayed, the user interface ambient light detector 37
0 to provide the current ambient light information and the display device 20
It is highly desirable to be able to accurately apply the inverse chromatic adaptation compensation each time the above electronic image is viewed. In such an embodiment, the camera 14 has a single confirmation image and modifies the confirmation image for immediate or subsequent observation based on the ambient light conditions being observed. The inverse chromatic adaptation compensation can likewise be applied to the transferred image or any other image shown on the display device 20.

Referring now to FIG. 33, an image of the scene is captured as an electronic image (24), digitized (26), calibrated for input and output (28), and stored (27). When the user selects (380) (eg, using the mode switch 170 shown in FIG. 32), the user interface ambient light detector 370 is activated and the color values are measured (38).
2). A color balance compensation is determined (384). The electronic image is retrieved from the storage unit (386), a color balance is obtained (388), and chromatic adaptation reverse compensation is performed and displayed (3).
6). The switch 170 is deactivated by the timer or the user, and stops the display device.

The tint compensation can be determined by either a predetermined value look-up table or the above procedure using inverse white balance. The camera 14 has a second image sensor,
It is presently preferred to use the "brightest object" inverse white balance scheme described above and shown in FIGS.

Referring now to FIG. 34, the camera 14 may alternatively have a color adjuster 310 having a function similar to that of the peripheral detector 172 shown in FIG.
In the camera of FIG. 34, the color adjuster 310 is indicated by a dashed line. The color controller 310 includes the second image sensor 3 as a sensor.
74a is used. The lens system 392 includes the second image sensor 37
Guide light to 4a. The electronic image captured by the second image sensor 374a is guided through the A / D converter 134, the pixel accumulator 300, the pixel combiner 304, and the color ratio calculator 308. The color controller further includes a scene light source value lookup table 2
70, a control unit 132, and an image memory 138a. These components are used in the form already described with respect to the camera of FIG. 13, except for the embodiment shown in FIG. 34, where the switch 294 is activated and the image processing unit 390 is used to store the memory 289. The electronic image held in is modified. (For clarity, some functions, such as peak value detectors, shown in FIG. 13 are not shown in FIG. 34, but can be incorporated and used as described above.) The channel gain adjuster 311 used in FIG. 13 is unnecessary here because the image adjustment is performed on the stored electronic image instead of correcting the gain applied by the image sensor. Here, like elsewhere, a plurality of components that provide similar functions, such as A / D converter 134, can be prepared for different applications and control a single set of components. However, different functions can be provided as needed. The camera 14 shown in FIG. 13 can be further modified to include the functions shown in FIG. 34 to display the image held in the memory. It is also possible to eliminate the channel gain adjuster and use an image processor to modify all images if necessary.

User Interface Ambient Light Detector 370
Detects the surrounding luminance with the user interface 154,
The brightness of the image display device 20 can be adjusted accordingly. Variable output displays capable of providing this function are known to those skilled in the art.

Other Features of the Invention A camera that can be used to capture an image of a scene illuminated by ambient light, comprising: a body, disposed within the body,
An electronic image sensor that captures an image of ambient light as a multicolor electronic image, a color detector that is disposed in the main body, measures the ambient light to provide a color value, and is disposed in the main body, A reference table having the color values assigned to one of the light sources and one or more of the non-predetermined light sources, wherein each of the non-predetermined light sources has a tint with respect to the predetermined light source, and is arranged outside the main body. The camera having a user interface for displaying the electronic image and an instruction of the light source to which the color value is assigned.

2. The camera of claim 1, wherein the color detector has three sub-detectors, each of the sub-detectors has a maximum spectral sensitivity for a different color of the ambient light, and the color value is a three-color system.

[0200] 3. A camera that can be used to capture an image of a scene illuminated by ambient light, comprising: a main body, a display device disposed outside the main body, and a peripheral device disposed inside the main body, the peripheral light being a multicolor electronic image. An electronic image sensor for capturing an image, a color detector disposed in the main body and measuring the ambient light to provide a color value, and a predetermined light source and a light source other than the predetermined light source disposed in the main body. A reference table having the color values assigned to one or more of the light sources, each of the light sources other than the predetermined light source having a tint for the predetermined light source, and a control system for transferring the electronic image to the display device. And, when the assigned light source is one of the light sources other than the predetermined light source, the control system balances the color of the electronic image, the predetermined light source, and the light source to which the color value is allocated. The camera that informs the color

4. The camera of claim 3 having a storage capture medium that is color balanced for the predetermined light source.

5. 3. The camera according to the above 3, wherein the relative colors correspond to a decrease in correlated color temperature.

6. At least one of the reference light sources is 5
The camera of claim 3 having a correlated color temperature of less than 000 K.

7. The camera according to the above 3, wherein the color detector is operably connected to the image sensor, and the color value of the electronic image is measured.

8. 3. The camera according to 3 above, further comprising an ambient light sensor attached to the main body, wherein the ambient light sensor is operably connected to the color detector independently of the imaging device.

9. A camera operable to capture an image of a scene illuminated with ambient light, comprising: a main body; an electronic imaging device disposed within the main body, for capturing an image of the ambient light as a multicolor electronic image; A color detector arranged in the main body and measuring the color value of the electronic image, and the color value arranged in the main body and assigned to one of a plurality of reference light sources, wherein each of the reference light sources has a different correlation. Reference table with color temperature, for the correlated color temperature of the assigned reference light source,
The camera, comprising: a control system that provides a confirmation image by balancing the color of the electronic image; and a display device that is disposed outside the main body and that displays the confirmation image.

10. At least one of the reference light sources,
The camera of claim 9 having a correlated color temperature of less than 5000 K.

11. Further, a film capturing unit mounted in the main body, an optical system for guiding the image of the ambient light to the film capturing unit and the electronic image sensor, and an optical system that can be selectively mounted on the main body and selectively activated. The camera according to the above item 9, further comprising a shutter opening unit that simultaneously guides the image of the ambient light to the image sensor.

12. The camera of claim 11, wherein one or more of the reference light sources are each equal to a correlated color temperature of an illumination source, partially normalized by reducing a predetermined baking tint for the illumination source.

13. The camera of claim 9 wherein said electronic image is pixelated and said color detector comprises a digital color sampling circuit for sampling a plurality of pixels of said electronic image.

14. The camera of claim 13, wherein the electronic image has three sub-images, each of the sub-images having a different color, and wherein the digital color sampling circuit samples the brightest pixel of the sub-image.

[0212] 15. The camera of claim 9, wherein the electron capture unit further comprises an array imager and a filter disposed on the imager.

16. The camera of claim 9, wherein said color detector samples said electronic image.

[0214] 17. The camera of claim 9, further comprising a film capture unit attached to the body.

18. What is claimed is: 1. A camera usable for capturing an image of a scene illuminated with ambient light, comprising: a main body; an electronic imaging unit disposed in the main body, for capturing an image of the ambient light as a three-color electronic image; A color detector disposed in the main body, for measuring the color value of the ambient light, and provided in the main body, including the color value assigned to one of a plurality of reference light sources, and providing an assigned reference light source. A reference table including one or more non-predetermined light sources, wherein the reference light source has daylight and a correlated color temperature lower than the correlated color temperature of daylight; and the electronic imaging unit and the reference table are operable. When the reference light source is daylight, the color balance of the electronic image is maintained, and when the reference light source is one of the light sources other than the predetermined light source, the electronic image is set to a lower correlated color temperature. Color balance and check image It said camera having a control system that provides a display device which is arranged outside the main body, displaying the confirmation image.

19. The reduction of the color temperature of the electronic image from the color temperature of the assigned reference light source to daylight;
18. The camera of claim 18, wherein the camera is proportional to the direction of white balance correction of the electronic image.

20. 20. The camera of claim 19, wherein one or more of the reference light sources are each proportional to a correlated color temperature of an illumination source, and are partially normalized by reducing a predetermined baking tint for that illumination source.

21. The camera according to the above 20, further comprising a film capturing unit attached to the main body, and an optical system for guiding the image of the ambient light to the film capturing unit and the electronic imaging unit.

22. An imaging method usable in ambient light, wherein an image of the ambient light is captured as an electronic image in a camera, the color value of the ambient light is measured, and one of the predetermined light sources and one or more light sources other than the predetermined light source To adapt the color value of the ambient light to
Allocate a light source, each of the non-predetermined light sources is provided with a tint for the predetermined light source, transfer the electronic image to a display device, balance the color of the electronic image during the transfer, and assign the light source. When the light source is one of the light sources other than the predetermined light source, a method of notifying a color to the predetermined light source and the assigned light source.

23. 23. The method of claim 22, further comprising capturing the ambient light image on a storage capture medium that is color balanced to the predetermined light source.

24. The method of claim 22, wherein said measuring further comprises sampling said electronic image.

25. The method of claim 22, further comprising changing the ambient light between the capturing of the ambient light and the measurement.

26. The method of claim 22, further comprising calibrating the electronic image against the display device prior to the transfer.

27. A method of imaging a scene illuminated with ambient light, capturing an image of ambient light as an electronic image in a camera, measuring the color values of the electronic image, adapting the color values to a plurality of reference light sources, Assigning a reference light source, each of the reference light sources having a different correlated color temperature, and providing a confirmation image by balancing the color of the electronic image with respect to the assigned correlated color temperature of the reference light source; How to display an image.

28. The method of claim 27, further comprising capturing the ambient light image on a storage capture medium that is color balanced to one of the reference light sources.

29. One or more of the reference light sources are each equal to the correlated color temperature of an illumination source and are partially standardized by reducing a predetermined baking tint for each of the storage medium and the reference light source. 28. The method according to the above item 28.

30. The method of claim 27, further comprising sampling the electronic image with the measurement.

31. The method of claim 27, wherein the electronic image is calibrated to the display device prior to the displaying.

32. The method of claim 27, wherein the capturing further filters the ambient light image into three differently colored sub-images.

33. The method of claim 32, further comprising sampling each of the sub-images with the measurement.

34. The method of claim 27, further comprising capturing a latent image of the film simultaneously with said capturing of said electronic image.

35. The at least one reference light source being equal to the correlated color temperature of an irradiation source, and partially standardized by reducing a predetermined baking tint for the irradiation source;
Method 4.

36. An imaging method usable with ambient light, capturing an image of ambient light as an electronic image in a camera,
Measuring the color values of the electronic image, adapting the color values to a plurality of reference light sources, assigning reference light sources, the reference light sources each having a different correlated color temperature, and duplicating the electronic image to first And providing a second copy, and for the correlated color temperature of the assigned reference light source, balance the color of the first copy of the electronic image to be different from the first copy of the electronic image. A method of balancing the color of the second copy of the electronic image and displaying the first and second copies of the electronic image on a display device attached to the camera.

37. 37. The method of claim 36, further comprising selectively changing and displaying the first and second replicas in the display.

38. The method of claim 36, further comprising displaying the first replica during a period following the capturing and displaying the second replica after the end of the period.

39. 38. The method as in claim 38, further comprising deleting the first replica following the time period.

40. The method of claim 38, further comprising selectively displaying said second replica during said time period.

41. The method of claim 36, further comprising calibrating the replica against the display prior to the displaying.

The above and other features and objects of the present invention, and a method of realizing the same will become more apparent by referring to the following description of embodiments of the present invention, taken in conjunction with the accompanying drawings. Better understood.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of one embodiment of a system.

FIG. 2 is a schematic diagram of another embodiment of the system.

FIG. 3 is a system diagram of an embodiment of a camera.

FIG. 4 is a system diagram of another embodiment of the camera.

FIG. 5 is a system diagram of still another embodiment of the camera.

FIG. 6 is a rear perspective view of the camera of FIG. 3;

FIG. 7 is a partial exploded view of the camera of FIG. 3;

FIG. 8 is a diagram illustrating the operation of one embodiment of a camera that provides an exemplary tint signal.

FIG. 9 is a schematic diagram similar to FIG. 3, showing a modified embodiment of the camera.

FIG. 10 is a schematic diagram of an embodiment of an imaging method.

FIG. 11 is a schematic diagram similar to FIG. 3, showing another variant of the camera.

12 is a diagram illustrating a reference table of the camera in FIG. 11, which is illustrated as a diagram of an RGB color space.

FIG. 13 is a simplified system diagram of the camera of FIG. 11;

FIG. 14 is a flowchart showing the operation of the camera of FIG. 11;

FIG. 15 is a simplified system diagram showing a modification of the camera of FIG. 11;

16 is a detailed system diagram of a color balance circuit of the camera in FIG.

FIG. 17 is a diagram of an RGB color space illustrating a white balance of the camera of FIG. 15;

18 is a diagram of an RGB color space illustrating a color balance of the camera in FIG.

FIG. 19 is a diagram in which an electronic image is divided into blocks for white balance and color balance in FIGS.

FIG. 20 is a diagram showing a brightest block signal area in a DG-DI plane for color balance and white balance in FIGS. 17 and 18;

FIG. 21 is a partial schematic diagram of one embodiment of a camera showing details of an ambient light detector separated from an image sensor.

FIG. 22 is a diagram illustrating an embodiment of an imaging method.

FIG. 23 is a semi-schematic perspective view of another embodiment of a camera for capturing an image of a scene illuminated by a fluorescent light.

FIG. 24 is a rear view of another embodiment of the camera.

25 is a perspective view of an image display device of the camera of FIG. 24 and a display device in which instructions and information are combined.

FIG. 26 is a rear view of still another embodiment of a camera showing a display device for displaying images for confirmation and instructions.

FIG. 27 is the same as FIG. 26, but showing a transferred image.

FIG. 28 is a flowchart showing a second scheme of a tint signal.

29 is a partially enlarged view of the view of the camera of FIG. 3, modified to include an instruction display device and an instruction display drive.

FIG. 30 illustrates the operation of one embodiment of a camera, providing an exemplary tint signal adjusted to ambient light at the time the image is displayed.

FIG. 31 is a perspective view showing a modification of the camera of FIG. 21 operating according to FIG. 30;

FIG. 32 is a system diagram of the camera of FIG. 31.

FIG. 33 is a schematic diagram of the electronic capture and display device of the camera of FIG. 31.

FIG. 34 is a schematic diagram of a user interface of an ambient light detector and related functions of one embodiment of a camera.

[Explanation of symbols]

14 camera, 54 body, 84 image sensor, 130
Control system, 154 user interface, 172
Color detector, 270 Lookup table.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 7/28 G03B 7/28 5C022 17/18 17/18 Z 5C065 17/48 17/48 5C082 19/06 19/06 H04N 5/225 H04N 5/225 A // G09G 5/00 510 G09G 5/00 510M F term (reference) 2H002 DB17 DB24 GA32 GA33 HA04 HA28 2H054 BB07 2H088 EA03 EA25 MA20 2H102 AA71 BB01 BB08 CA03 2H022 A18 AB06 AB15 AB36 AB40 AB66 AC02 AC03 AC32 AC42 AC73 AC74 5C065 AA06 BB02 BB41 CC01 CC08 DD02 FF03 FF10 GG18 HH02 5C082 AA27 CB03 MM09

Claims (4)

[Claims] 1. A camera which can be used by capturing an image of a scene illuminated by ambient light, comprising: a main body; and an electronic imaging device disposed in the main body, the electronic imaging capturing a peripheral light image as a multicolor electronic image. An element, a color detector disposed in the main body and measuring the ambient light to provide a color value; and A look-up table having the color values assigned to one or more non-predetermined light sources, and a user interface disposed outside the body and displaying an indication of the light source to which the electronic image and the color values are assigned. And a camera having: 2. A camera that can be used by capturing an image of a scene illuminated by ambient light, comprising: a main body; and an electronic imaging device disposed in the main body and capturing an image of the ambient light as a multicolor electronic image. An element, a color detector disposed in the body and measuring a color value of the electronic image; and a plurality of references arranged in the body to provide reference light sources each having a different correlated color temperature. A reference table having the color values assigned to one of the light sources, and a control system for providing a confirmation image by balancing the correlated color temperature of the assigned reference light source with respect to the electronic image, A display device that is disposed outside the main body and displays the confirmation image. 3. An imaging method usable in ambient light, comprising: capturing an image of ambient light as an electronic image in a camera, measuring a color value of the ambient light, and using one predetermined light source and one or more A light source other than a predetermined light source is assigned a light source by adapting the color value of the ambient light, and each of the non-predetermined light sources has a color correlated with the predetermined light source, and the electronic image is transferred to a display device. And a method of, in the case where the assigned light source is a light source other than the predetermined light source during the transfer, giving a tint correlated to the predetermined light source and the allocated light source to the electronic image to achieve color balance. 4. An imaging method usable in ambient light, comprising: capturing an image of ambient light as an electronic image in a camera; measuring a color value of the electronic image; Adapting the color values and assigning reference light sources, each of the reference light sources having a different correlated color temperature, duplicating the electronic image to provide first and second reproductions, For a correlated correlated color temperature, balance the color of the first copy of the electronic image, differing from the first copy of the electronic image, and color the second copy of the electronic image. A method of balancing and displaying said first and second reproductions of said electronic image on a display device attached to said camera.